Why this code generate segmentation fault?

Question

#include<stdio.h>
int sum(int a)
{int b;
if(a==1)
{
return 1;
}
else
return b=sum(a+sum(a-1));

}
int main()
{int num;
printf("Enter a number for sum:");
int num;
scanf("%d",&num);
int res=0;
res=sum(num);
printf("SUM : %d",res);
return 0;
}

Answer 1

Pavan Rajak

You have declared b inside sum method and assigned value so working till infinite time so what you are trying to do?

many mistakes in your logic:

#include<stdio.h>

int sum(int a) {
//int b;

if(a == 1)
return 1;
else
return a + sum(a - 1);
}

int main() {
printf("Enter a number for sum:");
int num;
scanf("%d",&num);

int res=sum(num);

printf("SUM : %d",res);

return 0;
}