C++ experiment---time difference

Time difference

Description
defines a class Time, which contains three attributes: hour, minute, and second. Define its constructor Time(int, int, int) to initialize the hour, minute, and second respectively. Overloaded subtraction operator, used to find the number of seconds (non-negative integer) between two times.
Input
has 2 lines. Each line represents 1 time, including three values ​​of hour, minute, and second. The input is a legal 24-hour time. See the example for
Output
.
Sample Input

12 10 10
10 20 20

Sample Output

Deference is 6590 seconds.

Title given code

int main()
{
    
    
    int a, b, c;
    cin>>a>>b>>c;
    Time t1(a, b, c);
    cin>>a>>b>>c;
    Time t2(a, b, c);
    cout<<"Deference is "<<(t2 - t1)<<" seconds."<<endl;
    return 0;
}

code：

#include<iostream>
#include<math.h>

using namespace std;


class Time{
    
    
	int hh;//小时
	int mm;//分钟
	int ss;//秒
public:
	Time(int h,int m,int s){
    
    //构造函数
		hh=h;
		mm=m;
		ss=s;
	}
	
	friend int operator -(const Time &t1,const Time &t2){
    
    
		int time1=t1.hh*3600+t1.mm*60+t1.ss;
		int time2=t2.hh*3600+t2.mm*60+t2.ss;
		return abs(time1-time2);//注意返回非负整数
	}
	
};


int main()
{
    
    
    int a, b, c;
    cin>>a>>b>>c;
    Time t1(a, b, c);
    cin>>a>>b>>c;
    Time t2(a, b, c);
    cout<<"Deference is "<<(t2 - t1)<<" seconds."<<endl;
    return 0;
}