HDU 2113 Secret Number

#include <bits/stdc++.h>
using namespace std;

const int maxn = 1e5 + 10;
char s[maxn];

int main() {
    int n;
    int cnt = 0;
    while(~scanf("%d", &n)) {
        cnt ++;
        if(cnt != 1) printf("\n");
        itoa(n, s, 10);
        int len = strlen(s);
        int sum = 0;

        for(int i = 0; i < len; i ++) {
            if(s[i] % 2 == 0)
                sum += (s[i] - ‘0‘);
        }

        printf("%d\n", sum);
    }

    return 0;
}