题解 | #数位之和#

#include <stdio.h>

int sum(int n) {
    int s = 0;
    while(n > 0) {
        s += n % 10;
        n /= 10;
    }
    return s;
}

int main() {
    int n;
    scanf("%d", &n);
    printf("%d\n", sum(n));
    return 0;
}