题目要求：再加两个功能：正数计时和倒数计时
#include
#include
using namespace std;
class Time {
public:
int hour;
int minute;
int sec;
Time() {
int hour=0;
minute = 0;
sec = 0;
}
Time(int h,int m, int s):hour(h),minute(m), sec(s)
{}
Time& operator++();
Time& operator--();
friend Time& operator+=(Time& a, Time& b);
friend Time& operator-=(Time& a, Time& b);
void Print();
};
Time& Time::operator++() {
sec++;
if (sec >= 60) {
sec -= 60;
minute++;
if(minute>=60){
minute-=60;
hour++;
}
}
return *this;
}
Time& Time::operator--() {
sec--;
if (sec < 0) {
sec += 60;
minute--;
if(minute<0){
minute+=60;
hour--;
}
}
return *this;
}
Time& operator+=(Time& a, Time& b) {
int hour;
int minute;
int sec;
if (a.sec + b.sec >= 60) {
a.sec += b.sec;
a.sec -= 60;
a.minute++;
}
else {
a.sec += b.sec;
}
if (a.minute + b.minute >= 60) {
a.minute += b.minute;
a.minute -= 60;
hour++;
}
else {
a.minute += b.minute;
}
a.hour+=b.hour;
return a;
}
Time& operator-=(Time& a, Time& b) {
int hour;
int minute;
int sec;
int t1, t2, t;
t1 = a.hour*60*60+ a.minute * 60 + a.sec;
t2 = b.hour*60*60+b.minute * 60 + b.sec;
if (t1 >= t2) {
t = t1 - t2;
}
else {
t = t2 - t1;
}
a.hour = t/3600;
a.minute = t%/60;
a.sec = t % 60;这里有问题，研究清楚后改正
return a;
}
void Time::Print() {
cout << "当前时间是：";
cout < } int main() { Time time1, time2, time3; int a; cout << "请输入小时："<< endl; cin >>time1.hour; cout << "请输入分钟：" << endl; cin >> time1.minute; cout << "请输入秒钟：" << endl; cin >> time1.sec; cout << "当前时间是：" << time1.hour<<"时:"< cout << "--------------------------------" << endl; cout << "请输入操作" << endl << "1.整数计时" << endl << "2.倒数计时" << endl << "3.时间相加" << endl << "4.时间相减" << endl; cout << "--------------------------------" << endl; while (scanf("%d", &a) != EOF) { switch (a) { case 1: for (int i = 0; i < 8; i++) { ++time1; Sleep(1000); time1.Print(); } break; case 2: for (int i = 0; i < 8; i++) { --time1; Sleep(1000); time1.Print(); } break; case 3: cout << "请输入需要相加的时间（时钟）" << endl; cin >> time2.hour; cout << "请输入需要相加的时间（分钟）" << endl; cin >> time2.minute; cout << "请输入需要相加的时间（秒钟）" << endl; cin >> time2.sec; time1 += time2; time1.Print(); break; case 4: cout << "请输入需要相减的时间（时钟）" << endl; cin >> time3.hour; cout << "请输入需要相减的时间（分钟）" << endl; cin >> time3.minute; cout << "请输入需要相减的时间（秒钟）" << endl; cin >> time3.sec; time1 -= time3; time1.Print(); break; } } return 0; }
