c - Prime Generator(spoj)

Question

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Here I defined three function, called them selves one within another. Function call is not being done

#include<stdio.h>
int primegen(int x1,int x2);
int isprime(int j);
int main(){
   int x,n1,n2,i;
   printf("Enter the number of test cases:");
   scanf("%d",&x);
    for(i=0;i<x;i++){
      printf("enter the starting point and ending point:");
      scanf("%d %d",&n1,&n2);
      primegen(n1,n2);
    }
    return 0;
}

int primegen(int x1,int x2){
   int k;
   if(x2>x1){
      for(k=x1;k<x2;k++){
        if(isprime(k))
        {
           printf("%d",k);
        }
      }
      return 0;
   }
}

int isprime(int j){
   int i,c=0;
   for (i=1;i<=j;i++)
   {
     if(j%i==0){
        c++;
     }
     if(c!=2){
        return 0;
     }
     else{
        return 1;
     }
   }
}

Output

There is no output for this code.

Answer 1

Take following outside loop:

if(c!=2){
    return 0;
}
else{
    return 1;
}