How there is a output 14?

Question

int f(int*a,int n)
{
if(n<=0) return 0;
else if(*a%2==0)
return *a + f(a+1,n-1);
else
return *a - f(a+1,n-1);
}
int main(){
int a[] = {12,7,5};
printf("%i",f(a,3));
}

Answer 1

You're calling f() with int *a = 12 and n = 3.

f(12, 3)
n <= 0 ? false
*a % 2 == 0? true

=> return 12 + f(13, 2)

f(13, 2)
n <= 0 ? false
*a % 2 == 0? false

=> return 13 - f(14, 1)

f(14, 1)
n <= 0 ? false
*a % 2 == 0? true

=> return 14 + f(15, 0)

f(15, 0)
n <= 0 ? true

=> return 0

==> return 14 + 0 = 14