1
2
  -2021
..  
 
(    )
  :    : 75
:               
1. (a)        ? (725.55)  ,   
   
()         
2. ()             

(b) Constant, Variable     ?      
Constants    
3.            :
()  
()  .
4. (a)      gets()  puts()    
(b) printf()     ? C        ? 
 putchar   
5. ()       If-else       
 
2
2
(b) Continue     ?      break
  
6.   ?           - 
       ?     
7. (a)              
  
(b)               

8. (a)  ?       ?       
?    
(b)           
      ?
3
2
  -2021
..  
 
(    )
  :    : 75
:               
1. (a)        ? (725.55)  ,   
   
()         
:          
        ,         
            "" ,   
         !       
 :
1.   ( 10):        10  (0-9) 
        -   
2.   ( 2):     !      
 : 0  1.  "   "    
3.   ( 8):,     (0-7)    
     
4.   ( 16):      16  (0-9  AF) 
              
,    725.55725.55725.55   (  )  ,
           -     
-    !
4
2
 :725.55
              
     ,        :
1.    :725
2.  : 0.550.550.55
    -  
1.      ( 2)
1:  725    
        :
  2    ,      
      
           
:
1. 725÷2=362,  = 111
2. 362÷2=181,  = 000
3. 181÷2=901,  = 111
4. 90÷2=45,  = 000
5. 45÷2=22,  = 111
6. 22÷2=11,  = 000
7. 11÷2=5,  = 111
8. 5÷2=2,  = 111
9. 2÷2=12,  = 000
10. 1÷2=01,  = 111
725  : 1011010101
 :   0.55    
  ,   2               
     0        
5
2
:
1. 0.55×2=1.10,  = 1
2. 0.10×2=0.20,  = 0
3. 0.20×2=0.40,  = 0
4. 0.40×2=0.80,  = 0
5. 0.80×2=1.60,  = 1
6. 0.60×2=1.20,  = 1
7. 0.20×2=0.40,  = 000 ()
0.55  :0.100011...
 :1011010101.100011...
2.      ( 8)
1:  725    
  ,    2   8   
:
1. 725÷8=90,  = 555
2. 90÷8=11,  = 222
3. 11÷8=1,  = 333
4. 1÷8=0,  = 111
725  :1325
 :  0.550.550.55    
  , 8        
:
1. 0.55×8=4.40,  = 4
2. 0.40×8=3.20,  = 3
3. 0.20×8=1.60,  = 1
4. 0.60×8=4.80,  = 4
5. 0.80×8=6.40,  = 6
6
2
 0.55: 0.43146...
 :1325.43146...
3.       ( 16)
1:  725725725    
  , 16  
:
1. 725÷16=45,  = 5
2. 45÷16=2,  = 131313 (  DDD      )
3. 2÷16=0,  = 2
725  : 2D5
 :  0.550.550.55    
  , 16         
:
1. 0.55×16=8.80,  = 8
2. 0.80×16=12.80,  = 121212 (  CCC     )
3. 0.80×16=12.80 ( )
0.55  : 0.8C...
 : 2D5.8C...
725.55   
1. : 1011010101.
2. : 1325.43146.
3. : 2D5.8C..
  ( )
          :
    (0  1) 
    (3  ) 
     (4  )
7
2
                 
   ,         !
()    ?
              (   C
     )  C, Python  Java        
,   ,               
                 
  
       ?
:   (     )      
          
   --     
              , 
          
     (   )   (     
  )       
  : 
             ,    
             :
1.  
2.     
3.   10   .
4.  .
5.    
6.  
            ,      
?    !
:     
8
2
                 
        :
1. 
2.        num1     
3.         num2     
4. num1  num2  ,    sum     
5.     .
6. 
   C       :
      (       )
1.   :        
2.  :         
3.      "", " ", "", "", ""    
 
4.    :  ;    {}   -  
       
5.    :            
,    
 2:     
                   
 :
9
2
1. 
2.         num     
3.   2  
4.   0   "  "  
5. , "  "  
6. 
  :
   
               
             
  :             
   :   ,      
 -        
  :       
           ""    
 :
1. 
2. 
3.    
4.  
10
2
5.  
6.  
7.    
8. 
,   ,            (    
     !)
   !
     :           :
1.         
2.      ,    
3.      

       ,          
         ,        
                 
    ,           
2. ()             

(b) Constant, Variable     ?      
Constants    
:            
      ,         ! 
             :  
          ,      
 C           !

 (C   )
C     ()             
       :
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2
1.  (int)   
                 
     -  ,     
:   16-    -32,768  32,767 
:
o int age = 25; //      
o int numberOfApples = 100; //     ,    
2.  ()  
          - ,     3.14   7.25
           
:4 
:
o  pi = 3.14; // π     
o   = 5.67; //      
3.  ()    
        ,      !    
    
: 8 
:
o double distanceToSun = 149600000.123456; //     
o double scientificValue = 0.000002345; //       
4.  ()   
              ,   
    
:1 
:
o char  = 'A'; //    
o char symbol = '#'; //      
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2
5.  ()  
            ?    !
             
:
o           ,  void
castSpell() { ... }
6.  (_Bool) 

       :    ()  ()   
 "   ?"       
:1 
:
o _Bool isDoorOpen = 1; //        
o _Bool isLampOn = 0; //        
:    
-,              
    :
1.   
  :          
 :       ,     

:
2.   
:         .
:     
13
2
:
 int smallNumber = 32000; // 
long int largeNumber = 123456789; // 
   ?
    
  ,       
       :
1.  :int  unsigned int   .
2.   :      .
3.  :   .
4. / : _Bool   .
5.    :   .
 
 ( )
          :
#  <stdio.h>
  () {
int  = 25; //
  = 3.14; //  
  = 1.23456789; //   
char  = 'A'; //  
_Bool isStudent = 1; //   (/)
(": %d\n", );
("pi  : %.2f\n", pi);
(" : %.8f\n", bigNumber);
(": %c\n", );
("  ? %d\n", isStudent);
0 ;
14
2
}
:

: 25
  : 3.14
 : 1.23456789
:
  ? 1
        
             :
"  ,      ,    ,   ,   ,
  !"

       ,          
        ,    ()   
        
()     :   
:            ,    
  ,          :      
-             
: 
 -               , 
            ,      
      ( )       ,   
  :
"  5 ,     ,"         
: 
 ,            ,
15
2
",   10 ,"    , " ,  20    ,"     
           -     
        
 ,               
          ,       
      C     :
 1:
#  <stdio.h>
  () {
const int MAX_AGE = 100; //    
("  : %d\n", MAX_AGE);
// MAX_AGE = 110; //      MAX_AGE   
0 ;
}
, MAX_AGE    const        , 
  (100)    
 2:
#  <stdio.h>
  () {
int age = 20; //    
(" : %d\n", );
 = 25; //     
(" : %d\n", );
0 ;
}
  ,           20  25   
16
2
   :
      ,           , 
     :
""
"  !"
 ,      (")         
             
     ?
        :
1.  :    .
2.   :    .
3.  :  ,  ": ", ":   "
   
#  <stdio.h>
  () {
const char *greeting = ", !"; //  
printf("%s\n", ); //   : , !
// [0] = 'h'; //         
0 ;
}
  :
", !"        
      (, [0] = 'h';)      
    
 :  
17
2
         :
1.      (" ")    ,  

2. :   ( = 50).           
,  :
       -   
      -   
     ?

   (   )
  (PI = 3.14)     

    (    )
 ,               
C       
C                :
char [] = "";
           : | A | l | i | c | e | \0 |   \0
     
 
C           :
():     
strcpy():      .
strcmp():    .
   :
#  <stdio.h>
#  <.h>
18
2
  () {
char name1[] = "";
 2[] = "";
//    
 (strcmp(name1, name2) == 0) {
("  .\n");
}  {
(" - .\n");
}
0 ;
}
:     
 :
1. : , ,  const   .
2. :, ,     
3.  :    (")   ,       

                   
      :            
     !
19
2
3.            :
()  
()  .
:- ,               ,  
        , , ,        
  !      ,        
                
              
  ( ) 󼘆󼘇󼙂󼛌󼛍󼛎󼙄󼙅󼛏󼙆󼙇󼙈󼘐󼛐󼘑󼛑󼘒󼛒󼛓󼛔󼘓󼘗󼘘󼘜󼛕󼘙󼘚󼘛
                
 (    )            
          :
1.  (+)
          :
int = 5,  = 3;
int  = a + b; //  = 8
 :           5   3 
,    8    
2.  (-)
         :
int = 5,  = 3;
int  = a - b; //  = 2
 :         5     3 
 ,    2   
3.  (*)
         :
int = 5,  = 3;
int  = a * b; //  = 15
 :         5    
 3  ,   15  
20
2
4.  (/)
          :
int = 6,  = 3;
int  = a / b; //  = 2
 :         6    3 
,     2  
!   0             
     󺠣󺠤󺠥󺠦󺠧󺠨
5.  (%)
             :
int = 7,  = 3;
int  = a % b; //  = 1
 :          7   3   
  ,  1    
  ( ) 󼘆󼘇󼘈󼛂󼘊󼘋󼘭󼛃󼛄󼘮󼘯󼛅󼘰󼛆󼛇󼛈󼛉󼘱󼘲󼛊󼘳󼘴󼘵󼘶󼘷󼘸󼘗󼘘󼛋󼘙󼘜
   ,             
            :
1.  (+)
            
:
int a = +5; // a = 5
 :        , "  !"
2.  (-)
        .:
int = 5;
int  = -a; //  = -5
 :           5  , 
     -5  ()   
3.   (++)
              1   :
int = 5;
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2
++; // = 6
            ,   
     
 :
       :
o - (a++):     ,    
:
int = 5;
int b = a++; // b = 5, a = 6
o - (++a):   ,     .:
int = 5;
int b = ++a; // b = 6, a = 6
4.  (--)
      1  :
int = 5;
--; // = 4
 :             ,  
   
 :
    ,         :
o - (a--):     ,    :
int = 5;
int b = a--; // b = 5, a = 4
o - (--a):   ,     :
int = 5;
int b = --a; // b = 4, a = 4
     󷓠󷓡󷓢󷓣󷓤󷓥󷓨󷓩󷓪󷓫󷓦󷓧󷓬
           ,       
     
22
2
 :
#  <stdio.h>
  () {
int x = 10, y = 3;
//    
printf(": %d\n", x + y); // 13
(": %d\n", x - y); // 7
printf(": %d\n", x * y); // 30
(": %d\n", x / y); // 3
(": %d\n", x % y); // 1
//    
(": %d\n", +x); // 10
(": %d\n", -x); // -10
(" (): %d\n", x++); // 10,  x 11   
(" (): %d\n", ++x); // 12
(" (): %d\n", x--); // 12,  x 11   
(" (): %d\n", --x); // 10
0 ;
}
:
: 13
: 7
: 30
: 3
23
2
: 1
: 10
: -10
  (): 10
  (): 12
   (): 12
 (): 10
  
               
            ,   
          
 :
        
     ,         
4. (a)      gets()  puts()    
(b) printf()     ? C        ? 
 putchar   
:    , C     ,    , gets()  puts(), 
           :   
         
 ,           , "  
                  ?
       ,        !"
 , gets()  puts(),    , "!      !"
24
2
   (): 󹴮󹴯󹴰󹴱󹴲󹴳
gets()              
( )           -        
      
        ,  gets()      
 ,         ,    
gets()    :
1.      
2.        
3.       Enter    
gets()  :
#  <stdio.h>
  () {
char name[50]; //  ()      .
 ("   :");
gets(name); //    ,      
("   ,");
puts(name); //        
0 ;
}
  :
   :  
   ,  
  :
1.     " "   gets(name)   
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2
2. gets() ""              
3.  ,         puts()    (  
     !)
 puts() : 󹵪󹵧󹵨󹵩
puts()               
           ,      

puts()                  
        ,          ,  
  (  )  
puts()    :
1.         
2.      
3.             
puts()  :
#  <stdio.h>
  () {
char message[] = "     !";
puts(message); //          
0 ;
}
  :
     !
    puts()              
gets()  puts()     󷗛󷗜
      ,  gets()  puts()     !
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2
:  
#  <stdio.h>
  () {
  [50];
  [50];
//    
("   ?");
  ( );
//   
(", ");
 ( );
//        
("    ?");
  ( );
//   - 
("!   ");
 ( );
0 ;
}
  :
   ?  
,  
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2
    ? 
!     
gets()    󺪸󺪹
gets()     ,     :       
              ,  
       
  :
 [5];
gets(smallArray); //  " "   ,       

   (   )    ,      
     
 : fgets()
      , C   gets()   fgets()    
            ,     

fgets()  :
fgets(, , stdin);
: fgets()   
#  <stdio.h>
  () {
 [50];
 ("   :");
fgets(name, sizeof(name), stdin); //          

(", ");
 ();
28
2
0 ;
}
  :
   :  
,  
:gets()  puts()        󷇴󷇵󷇶󷇷󷇸󷇹
          :
gets()         
puts()          (  )   
 gets()     ,      ,     C
            fgets()   ,
 gets()    puts()        
(b) printf()     ? C        ? 
 putchar   
() : printf()        ?
C    printf()            
              , :



     !
()    
()                 
  ,      :
,   : 42!”
       !”
29
2
          :
#include <stdio.h> // /     
  () {
int age = 20; //    
printf(",  %d   !\n", age); //         printf
  
0 ;
}
 
,  %d   !\n:   ,  printf()       
%d   ()    ,  \n       
:         %d    ,  :
,  20   !
printf()    ?
1. :      -  , ,     
2.  :      ,       , 
  ,              !
3. :         ?   !
(" %d   %d   ,   %.2f%%\n ", 45, 50, 90.0);
    :
%d     .
%.2f      (90.00)  
  :
 50   45  ,  90.00% 
30
2
putchar()    ?
,  putchar(),            -     
         :  printf()      ,
 putchar()         
   putchar()       :
#  <stdio.h>
  () {
putchar('H'); // H   
putchar('i'); //  i   
putchar('\n'); //      
0 ;
}
:

        putchar()        :
#  <stdio.h>
  () {
for (  = 'A';  <= 'Z'; ++) {
putchar(letter); // A  Z       
}
putchar('\n');
0 ;
}
:
 
31
2
printf()  putchar()  

()
()

,      
   
.
FLEXIBILITY
 ;      
 
 ;   
   
 

        
(  , %d  %f   )
;    

  
 ,      
  - 
 ,   
  :     
1. ():            
  ,          , 
          
2. ():    -  ,      
,      
             :
#  <stdio.h>
  () {
("  :    :\n");
(",      !\n\n");
("     :\n");
char message[] = "";
for (int i = 0; message[i] != '\0'; i++) {
putchar(message[i]); //  ""     
}
32
2
putchar('\n'); //  
0 ;
}
:
  : 
  :
,      !
     :
  ?
               printf() 
 
  -            
 ,   ,  putchar()   
5. ()       If-else       
 
(b) Continue     ?      break
  
:   : "      ---"
                
           -   
                 
        , ELSE,       
 
 ,   - ,    -          ,
         IF  ELSE     
IF-ELSE   
1.  IF 
:   , "        "
33
2
     , " !        ,  
 "
 ,     :
 ( ) {
("   .\n");
}
, IF       :     ?   ,    
    ,    
2. IF-ELSE 
:  , "   ,       
  
"
   :
"     
  ,   
  "
 :
 ( ) {
("    .\n");
}  {
("    .\n");
}
, IF      (  ?)   ,       
 ,  ELSE                 ,
    
3. IF-ELSE IF 
:         , "    

       
          
 "
  : "    
 ,      
 , 
      "."
 :
 ( ) {
34
2
("    .\n");
}   (   ) {
("    .\n");
}   ( ) {
("   .\n");
}
, IF               ,    
4. IF-ELSE
:          "  ,     
        ,             , 
      "
      , "  ,         "
          
,    ,    ,    "
 :
 ( ) {
 ( ) {
("    .\n");
}  {
("    .\n");
}
}   (   ) {
("       .\n");
}
, IF               
 
5. -  (-    )
   IF-ELSE  ,         
          :
35
2
 
 
 
      :
 ( ) {
 '':
("   .\n");
;
 '':
("  .\n");
;
 '':
(" .\n");
;
 :
("   .\n");
}
 IF-ELSE   ,          
    
1.  IF     :    
2. IF-ELSE    :    ,    
3. IF-ELSE IF         
4.  IF-ELSE             
5. -             
 :    
         :
              
36
2
             
        
:
#  <stdio.h>
  () {
int isHungry = 1; // 1    
char snackPreference = 'S'; // 'S'   , 'T'   
 ( ) {
 ( == '') {
("    .\n");
}   (snackPreference == 'T') {
("    .\n");
}
}  {
("  .\n");
}
0 ;
}
  
- (IF-ELSE)             :
        
          
    .
IF-ELSE                
     !
37
2
  
      ,         
         ,       
,      IF-ELSE            
 , IF  ELSE       
()              
!
:                
            ,  ,
     ,            
  " "   
,                
,            ""      
                 

   : 
   ,           ,  
          :
"

,








,









 
"
  , continue             :
"









;





"
      
      continue   
    1  10        ,   5     
            C   :
#  <stdio.h>
  () {
for (int i = 1; i <= 10; i++) {
 (i == 5) {
 ; //  i 5       
}
38
2
printf("%d\n", i); //   
}
0 ;
}
   ?
1.  i = 1     1   ,      
2.  i = 5  ,  continue    ,   i = 5  
printf("%d\n", i);     
3.    ;   5      6, 7, 8, 9  10    

  :     
,                  
 ,       ,  ,         
        :
"





;





!"
               1  10  
     ,   5          
#  <stdio.h>
  () {
for (int i = 1; i <= 10; i++) {
 (i == 5) {
; //  i 5      
}
printf("%d\n", i); //   
}
0 ;
}
   ?
1.  i = 1     1   ,      
39
2
2.  i = 5  ,      ,         
3.  6  10    ,    
Continue  Break   
      continue  break   :

  
 

       .
       .
 

      
   

       
       
   
      
        
 

    5   
 5     
        
      
 :        ,       
    (    ,      )
:                 
(   )
Continue     ?
Continue      :
1.        
2.                 
  
  ,     1  10       :
#  <stdio.h>
40
2
  () {
for (int i = 1; i <= 10; i++) {
 (i % 2 == 0) {
 ; //    
}
printf("%d\n", i); //     
}
0 ;
}
:
1
3
5
7
9
, continue             
    
     ?
      :
1.             
2.               
  ,           :
#  <stdio.h>
  () {
int [] = {2, 4, 6, 8, 10};
int  = 6;
for (int i = 0; i < 5; i++) {
41
2
 ([i] == ) {
(" %d  %d \n", , i);
; //      
}
}
0 ;
}
:
 2  6 
,    6        
  
   ""     " "     :
              
       
                
 
6.   ?           - 
       ?     
::   ?
  ,                 
      ,    ,    
    ,    ,         
           ,       
         ,      ( ,
  ),       ( )  ,  ,  
   ,     ,      
     :
42
2
1. : :         ,    
 -     
2. :            
 
3.   :      ,      
         
4. :         
  
1.  :           , C ,
printf()  -           
2. - :        
  ,         ,     
  
     
       ,          
,                :
1. -   (   ).
2.  (       ).
       
   -    
     -   (, ,   - )
  ,                  
      ,              
(,    )
                 :
43
2
:
 :
1.  doubleNumber()  - , num  
2.   , num   ()   ,    main() 
             value  
  ,            
     
        ,         , 
     ,    ( )        
              
:
            :
44
2
:
 :
1.  doubleArray()  arr          
2.   ,              
       ,        
  
3. -   ,          
  
45
2
-          


   
      
.
 
       ,
    

  

      
    


       
  (  , int arr[]).

     
  (,   
 )
     
       ,           
1. -  :
o       ,  ,       
     ,     ,     
       
2. :
o ,              
    ,           
    ,         
    
1. -    :
o                -
         
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2
o :      
2.  :
o            ,   
           
o :      ,    , 
   

   -           
         -     
     ,          
          ,  ,   
        
7. (a)              
  
(b)               

:   : "  
  "
         ,         
      :       ,   
                ,  
    -            ,
            
,        :           
(  )         ,     
-          !
    :  
             (    ), 
              
47
2
  :
     (  5)          ,  
     "5"    
     10   ,          
 5           
   :   -         !  ,
 -                

   :  -
             ,  
 ,    
      ,         ,
             
    :
1.         ,  5,       , 
 1001
2.     1001 
3.     ,  1001   5  ,      10 

,      ,              
        ,       ,  
       !
      :    
                
   :
:
            ,    
    
 :
#  <stdio.h>
48
2
//           
(int * x, int * y) {
int ;
temp = *x; // temp   x    
*x = *y; //  y     x   
*y = temp; // temp   y   
}
  () {
int = 5,  = 10;
("  : a = %d, b = %d\n", a, b);
//     
(&a, &b);
("  : a = %d, b = %d\n", a, b);
0 ;
}
:
1.   :
o * ( ):       .
o & ( ):       .
2.     :
o main() ,      a = 5  b = 10.
o   swap(&a, &b)    ,   a  b      
 
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2
o  ,  x  y    a  b      
o *x  *y    ,  a  b        

3. :
o -  : a = 5, b = 10.
o -  : a = 10, b = 5.
o                
   
         ?
:        ,     ,  
  
 :              
     
 :        
  
        -       
          ,      
    ,      -    ,
      ,   ,     !
()    -      
:        ,  A   B,   
 A  5  ,   B  10        
        !      (  
)               C++
        
 :   ?
-      ,    -   
50
2
++ :
1.                   
            
2.        ,          
-    
 A   B      :
1.             (  ) 

2.         
3.  ,          
 ,   -  !    ,    -
      
    
 C++                :
#  <iostream>
    ;
//           
(int * x, int * y) {
int temp; //  
temp = *x; // temp  x    
*x = *y; // y   x   
*y = temp; // y  temp    
}
  () {
int , ;
//    
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2
cout << "    ( A): ";
>> ;
cout << "    ( B): ";
> ;
cout << "\n  :" << endl;
cout << " A =" << a << ",  B =" << b << endl;
//       a  b    
(&a, &b);
cout << "\n  :" << endl;
cout << " A =" << a << ",  B =" << b << endl;
0 ;
}
  -- 
1.  : 
(int* x, int* y)
           (int* x  int* y).
*x  *y            
2.  
int ;
 = *x;
temp *x ( A  )        
                 
   
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2
3.   -
*x = *y;
*y = ;
*y ( B  )   *x ( A)   
, temp (  A )     *y ( B)   
4.    
(&a, &b);
 &     a  b       
  , a  b          
  
 :
   ( A): 5
    ( B): 10
 :
-  :
 A = 5,  B = 10
-  :
 A = 10,  B = 5
    ?
      :
1.              
2.             
3.  :      ,    
    
 :        !
1.   ()     () 
2.                
         
53
2
3.    - ,       -  
       
  
                 
         !          
 
:    
1.      ,  
2.    -   :
o     .
o           
3.         
8. (a)  ?       ?       
?    
(b)           
      ?
:     
        ,   ,         
         ,       
                ,  
   !
  :  
                    
      ,           ( )  
()    :
     ,      
     ,      
54
2
   :
         
  ,        ,      

       :
int [5] = {10, 20, 30, 40, 50};
, ""    ,      
 :  
 ,        ,       
      ,  ,         -
               ,   
 
   :
            
         
       :
  {
 [50];
int ;
 ;
};
, ""     ,     :
 (   ),
 (),
 ( - )
      
55
2





      

     

      
   
  -   
      

 (, [0]) 
    .
  (, struct.member)  
   

     

      
   
       ,    (.)     
             
:
       :
#  <stdio.h>
  {
 [50];
int ;
 ;
};
  () {
//    
  p1;
//     
56
2
strcpy(p1.name, "");
p1. = 25;
p1.  = 5.4;
//      
(": %s\n", p1.name);
(": %d\n", p1.age);
(" : %.1f\n", p1. );
0 ;
}
:
: 
: 25
: 5.4
    :
1.  p1    () 
2.   (p1.name, p1.age, p1.height)    ,     
  
 :     
           :
1. :    30  ,        
       ()    ()  
int [30];
          ,  [0], [1],   
2. ,            ,  
 ,           :
  {
57
2
 [50];
int ;
int ;
};
  s1;
   (s1)             ,    
 - 
:        
          , :
1.  :
  {
 [50];
int  ;
 ;
};
2.  :

  {
 [50];
int ;
 ;
};
3. :

  {
 [50];
int ;
int ;
58
2
};
:    
-,         Arrays  Structures   
    ,            :
  {
 [50];
int  ;
 ;
};
struct Student students[30]; //    
  30     ,         
  
                 
      ,           
             .
:             ( )      
       ,              