C++ 代码
#include <cstdio>
#include <iostream>
using namespace std;
int main(){
int a;
int seconds;
int minutes;
int hours;
cin >>a;
hours=a/3600;
minutes=(a-(3600*hours))/60;
seconds=(a-(3600*hours+60*minutes));
printf("%d:%d:%d",hours,minutes,seconds);
}