50116. Play with digits

#include <stdio.h>
#include <stdlib.h>

// static inline int abs(int n){
//     return (n < 0) ? -n : n;
// }

int main(){
    int n;

    int flag = 0;
    int num_digits = 0;
    int odd = 0, even = 0;
    int cnt_zero = 0;

    int is_even = 0;
    while(scanf("%d", &n) != EOF){
        num_digits++;
        if(n % 2 == 0) is_even = 1;
        else is_even = 0;
        if(n == 0) cnt_zero++;

        if(flag) odd += n;
        else even += n;
        flag = !flag;
    }

    int is_mul11 = 0;
    if(abs(even - odd) % 11 == 0) is_mul11 = 1;

    printf("%d\n", num_digits);
    printf("%d\n", is_even);
    printf("%d\n", cnt_zero);
    printf("%d\n", is_mul11);

}