南昌大学航天杯第二届程序设计竞赛校赛网络同步赛 小q的时钟

#include <bits/stdc++.h>

#define ll long long

using namespace std;

int main()

{

     ll begin,end, time ;

     ll hh,mm,ss;

     while (~ scanf ( "%lld %lld" ,&begin,&end))

     {

         time =end-begin;

         hh= time /(3600);

         time = time %3600;

         mm= time /60;

         ss= time %60;

         printf ( "%02lld:%02lld:%02lld\n" ,hh,mm,ss);

     }

     return 0;

}