View Code of Problem 56

#include <iostream>
#include <cstdio>

using namespace std;

int main() {
    int h1, m1, s1;
    int h2, m2, s2;
    scanf("%d:%d:%d", &h1, &m1, &s1);
    scanf("%d:%d:%d", &h2, &m2, &s2);

    int n1, n2;
    n1 = h1 * 60 * 60 + m1 * 60 + s1;
    n2 = h2 * 60 * 60 + m2 * 60 + s2;

    int d;
    if (n1 >= n2) {
        d = n1 - n2;
    } else {
        d = n2 - n1;
    }

    int h, m, s;
    h = d / 3600;
    d -= h * 3600;
    m = d / 60;
    d -= m * 60;
    s = d;
    printf("%02d:%02d:%02d", h, m, s);
}