在C的GCC编译器中运行简单代码时出现运行时错误

Question

Following is the code:

#include <stdio.h>
void main ()
{
   int n1, n2, min, GCD, i;
   printf("Enter two nos. : ");
   scanf(" %d %d", &n1, &n2);
   min=(n1<n2)? n1: n2;
   for (i=0, i<min; ++i)
   { 
      if(n1%i==0 && n2%i==0)
          GCD=i;
   }
    printf("GCD is %d", GCD);
}

Please point out the mistake which is causing runtime error.

Answer 1

The modulus operator % will be problem when i is equal to zero. There is no need to start with i = 1 , every number is divisible by 1 . Start with i = 2 .

Also, you have a problem in the for loop, most likely due to a typo.

for (i=0, i<min; ++i)
       ^^^ That should be ;

Here's the loop with both fixes:

for (i=2; i<min; ++i)
{
   if(n1%i==0 && n2%i==0)
      GCD=i;
}

Other suggestions to improve your code:

1. Change the return type of main to int . That' what the standard expects.
2. Initialize GCD to 1 instead of leaving it uninitialized. You know that it has to be at least 1 .

Answer 2

 for (i=0, i<min; ++i) is wrong syntax

 for (i=0; i<min; ++i) is correct syntax

(n1%i) is actually dividing by 0; this is the reason for runtime error

return type of main is int as per standard