题目:https://pintia.cn/problem-sets/994805260223102976/problems/994805295203598336
#include<iostream>
using namespace std;
#include<time.h>
int main()
{
double c1,c2;
cin>>c1>>c2;
double click=100;
double sum;
sum=(c2-c1)/click;
int hh;
hh=sum/3600;
sum=(int)sum%3600;
int mm;
mm=sum/60;
int ss;
ss=(int)sum%60;
sum/=60;
if((int)(10*sum)%10>=5)
{
ss++;
}
cout<<hh<<":"<<mm<<":"<<ss;
return 0;
}