Codeforces Round #544 (Div. 3) A. Middle of the Contest(思维)

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

int main()
{
    int h1,h2,m1,m2;
    scanf("%d:%d %d:%d",&h1,&m1,&h2,&m2);
    int xx = (h2 - h1) * 60 + m2 - m1;
    xx /= 2;
    m1 += xx;
    h1 += m1 / 60;
    printf("%02d:%02d\n", h1, m1 % 60);
    return 0;
}