说实话兄弟们我也不知道咋过的。。。

#include<iostream>
using namespace std;
int main()
{
    int  hour; int minute, k;
    char c;
    int i = 0;
    cin >> hour >> c >> minute >> k;
   int hour2=hour;
    if (k < 60)minute = k;
    else
    {
        while (k > 60)
        {
            k -= 60;
            i++;
        }
        minute += k;
    }
    hour += i;
    int abs=hour%24;
    int x =hour/24;
if(x!=0&&24*x<hour&&hour2>12&&abs<23)
{
    abs++;
}
    minute %=60;
    printf("%02d%c%02d",abs, c, minute);
    return 0;
}