Language: C++

#include <stdio.h>

intmain(void){
    
    inta;
    scanf("%d"&a);
    printf("%d?\n",a*a*a);
  
    return ;
}


#include <stdio.h>

int main(void){

    int a,b;
    
    scanf("%d %d"&a,&b);
    printf("%d?\n%d",a*b);

    return 0;

}



#include <stdio.h>

int main(void){
    
    int s;
    int m;
    int h;
    
    scanf("%d",&s);
    s/60=m;
    s%60=s;
    
    m/60=h;
    m%60=m;
    
    h%60=h;

    scanf("%d:%d:%d:?\n",&h,&m,&s);
}


#include <stdio.h>

int main(void){

    int a;
    int b;
    
    scanf("%d %d"&a,&b);
    
    if(a<b){
        printf("%d<%d"&a,b);
    }
    else if(a>b){
        printf("%d>%d"&a,b);
    }
    else{
        printf("%d==%d"&a,b);
    }
    return 0;
  
}




#include <stdio.h>

int main(void){
    
    int a;
    int b;
    int c;
    
    scanf("%d %d %d"&a,&b,&c);
    
    if(a<b<c){
        puts("yes");
    }
    else{
        puts("no");
    }
    
    return 0;
    
}



#include <stdio.h>

int main(void){
    
    S[3]
    
    for( i = 0; i < 4; ++i ){
        scanf("%d",&s[i]);
    }
    
    
    
    
    
    
    
}


int main(void)
{
    
    for(i = 0; i <=1000; ++i ){
        puts("Hello World");
    }
    
    return 0;
}








#include <stdio.h>
int main(void)
{
    
    int W;
    int H;
    int x;
    int y;
    int z;
    
    
    scanf("%d %d %d %d %d",&W,&H,&x,&y,&z);
    
    
    
    
    return 0;
}

Compiler output:
a.cc:3:1: error: ISO C++ forbids declaration of 'intmain' with no type [-fpermissive]
    3 | intmain(void){
      | ^~~~~~~
a.cc: In function 'int intmain()':
a.cc:5:5: error: 'inta' was not declared in this scope; did you mean 'int'?
    5 |     inta;
      |     ^~~~
      |     int
a.cc:6:16: error: 'a' was not declared in this scope
    6 |     scanf("%d"&a);
      |                ^
a.cc:9:5: error: return-statement with no value, in function returning 'int' [-fpermissive]
    9 |     return ;
      |     ^~~~~~
a.cc: In function 'int main()':
a.cc:19:18: error: invalid operands of types 'const char [6]' and 'int' to binary 'operator&'
   19 |     scanf("%d %d"&a,&b);
      |           ~~~~~~~^~
      |           |       |
      |           |       int
      |           const char [6]
a.cc: At global scope:
a.cc:30:5: error: redefinition of 'int main()'
   30 | int main(void){
      |     ^~~~
a.cc:15:5: note: 'int main()' previously defined here
   15 | int main(void){
      |     ^~~~
a.cc: In function 'int main()':
a.cc:37:6: error: lvalue required as left operand of assignment
   37 |     s/60=m;
      |     ~^~~
a.cc:38:6: error: lvalue required as left operand of assignment
   38 |     s%60=s;
      |     ~^~~
a.cc:40:6: error: lvalue required as left operand of assignment
   40 |     m/60=h;
      |     ~^~~
a.cc:41:6: error: lvalue required as left operand of assignment
   41 |     m%60=m;
      |     ~^~~
a.cc:43:6: error: lvalue required as left operand of assignment
   43 |     h%60=h;
      |     ~^~~
a.cc: At global scope:
a.cc:51:5: error: redefinition of 'int main()'
   51 | int main(void){
      |     ^~~~
a.cc:15:5: note: 'int main()' previously defined here
   15 | int main(void){
      |     ^~~~
a.cc: In function 'int main()':
a.cc:56:18: error: invalid operands of types 'const char [6]' and 'int' to binary 'operator&'
   56 |     scanf("%d %d"&a,&b);
      |           ~~~~~~~^~
      |           |       |
      |           |       int
      |           const char [6]
a.cc:59:23: error: invalid operands of types 'const char [6]' and 'int' to binary 'operator&'
   59 |         printf("%d<%d"&a,b);
      |                ~~~~~~~^~
      |                |       |
      |                |       int
      |                const char [6]
a.cc:62:23: error: invalid operands of types 'const char [6]' and 'int' to binary 'operator&'
   62 |         printf("%d>%d"&a,b);
      |                ~~~~~~~^~
      |                |       |
      |                |       int
      |                const char [6]
a.cc:65:24: error: invalid operands of types 'const char [7]' and 'int' to binary 'operator&'
   65 |         printf("%d==%d"&a,b);
      |                ~~~~~~~~^~
      |                |        |
      |                |        int
      |                const char [7]
a.cc: At global scope:
a.cc:76:5: error: redefinition of 'int main()'
   76 | int main(void){
      |     ^~~~
a.cc:15:5: note: 'int main()' previously defined here
   15 | int main(void){
      |     ^~~~
a.cc: In function 'int main()':
a.cc:82:21: error: invalid operands of types 'const char [9]' and 'int' to binary 'operator&'
   82 |     scanf("%d %d %d"&a,&b,&c);
      |           ~~~~~~~~~~^~
      |           |          |
      |           |          int
      |           const char [9]
a.cc: At global scope:
a.cc:99:5: error: redefinition of 'int main()'
   99 | int main(void){
      |     ^~~~
a.cc:15:5: note: 'int main()' previously defined here
   15 | int main(void){
      |     ^~~~
a.cc: In function 'int main()':
a.cc:101:5: error: 'S' was not declared in this scope
  101 |     S[3]
      |     ^
a.cc:103:17: error: 'i' was not declared in this scope
  103 |     for( i = 0; i < 4; ++i ){
      |                 ^
a.cc: At global scope:
a.cc:116:5: error: redefinition of 'int main()'
  116 | int main(void)
      |     ^~~~
a.cc:15:5: note: 'int main()' previously defined here
   15 | int main(void){
      |     ^~~~
a.cc: In function 'int main()':
a.cc:119:9: error: 'i' was not declared in this scope
  119 |     for(i = 0; i <=1000; ++i ){
      |         ^
a.cc: At global scope:
a.cc:134:5: error: redefinition of 'int main()'
  134 | int main(void)
      |     ^~~~
a.cc:15:5: note: 'int main()' previously defined here
   15 | int main(void){
      |     ^~~~