Double Pointer

Code

#include <stdio.h>

void reassign_based_on_value(int **pp, int *n2_ptr) {
    if (**pp %2 == 0)
    {
        // assignig value n2 to n1
        **pp = *n2_ptr ;
    }
    // if n1 is odd do nothing 
}

int main() {
    int n1, n2;
    scanf("%d %d", &n1, &n2);

    int *p = &n1;

    reassign_based_on_value(&p, &n2);

    printf("%d", *p);

    return 0;
}

Solving Approach