2023.4.23

 1 #include <iostream>
 2 using namespace std;
 3 class Clock
 4 {
 5 public:
 6     Clock(int hour = 0,int minute = 0,int second = 0);
 7     void showTime()const;
 8     Clock& operator++();
 9     Clock operator++(int);
10 private:
11     int hour,minute,second;
12 };
13 Clock::Clock(int hour,int minute ,int second )
14 {
15     if(0<=hour&&hour<24&&0<=minute&&minute<60&&0<=second&&second<60)
16     {
17         this->hour = hour;
18         this->minute = minute;
19         this->second = second;
20     }
21     else
22         cout<<"Time error!"<<endl;
23 }
24 void Clock::showTime() const
25 {
26     cout<<hour<<":"<<minute<<":"<<second<<endl;
27 }
28 Clock&Clock::operator++()
29 {
30     second++;
31     if(second>=60)
32     {
33             second-=60;
34             minute++;
35             if(minute>=60)
36         {
37             minute-=60;
38             hour = (hour+1)%24;
39         }
40     }
41     return *this;
42 }
43 Clock Clock::operator++(int)
44 {
45    Clock old = *this;
46    ++(*this);
47    return old;
48 }
49 int main()
50 {
51     Clock myclock(23,59,59);
52     cout<<"First time output:";
53     myclock.showTime();
54     cout<<"show ++myclock:";
55     (++myclock).showTime();
56     cout<<"show myclock++:";
57     (myclock++).showTime();
58     return 0;
59 }