第九周任务二 （这是个问题）

#include <iostream>
using namespace std;
class CTime
{
private:
unsigned short int hour;    // 时
unsigned short int minute;  // 分
unsigned short int second;  // 秒
public:
CTime(int h=0,int m=0,int s=0):hour(h), minute(m), second(s){};
void setTime(int h,int m,int s);
void display();

//比较运算符(二目)的重载
bool operator > (CTime &t);
bool operator < (CTime &t);
bool operator >= (CTime &t);
bool operator <= (CTime &t);
bool operator == (CTime &t);
bool operator != (CTime &t);

//二目运算符的重载
CTime operator+(CTime &c);//返回c所规定的时、分、秒后的时间，例t1(8,20,25),t2(11,20,50)，t1+t2为:41:15
CTime operator-(CTime &c);//对照+理解
CTime operator+(int s);//返回s秒后的时间
CTime operator-(int s);//返回s秒前的时间

//一目运算符的重载
CTime operator++(int);//后置++，下一秒
CTime operator++();//前置++，下一秒
CTime operator--(int);//后置--，前一秒
CTime operator--();//前置--，前一秒

//赋值运算符的重载
CTime operator+=(CTime &c);
CTime operator-=(CTime &c);
CTime operator+=(int s);//返回s秒后的时间
CTime operator-=(int s);//返回s秒前的时间

friend ostream & operator <<(ostream &,CTime &);
friend istream & operator >>(istream &,CTime &);

};
//下面实现所有的运算符重载代码。
//为简化编程，请注意通过调用已有函数，利用好各函数之间的关系

void CTime::setTime(int h,int m,int s)
{
hour=h;
minute=m;
second=s;
}

void CTime::display()
{
cout<<hour<<":"<<minute<<":"<<second<<endl;
}

bool CTime::operator > (CTime &t)
{
if(hour>t.hour)
return true;
else if(minute>t.minute)
return true;
else if(second>t.second)
return true;
else
return false;
}

bool CTime::operator < (CTime &t)
{
if(hour<t.hour)
return true;
else if(minute<t.minute)
return true;
else if(second<t.second)
return true;
else
return false;
}

bool CTime::operator >= (CTime &t)
{
if(operator <(t)!=1)
return true;
else
return false;
}

bool CTime::operator <= (CTime &t)
{
if(operator >(t)!=1)
return true;
else
return false;
}

bool CTime::operator == (CTime &t)
{
if(operator <(t)!=1||operator >(t)!=1)
return true;
else
return false;
}

bool CTime::operator != (CTime &t)
{
if(operator <(t)==1||operator >(t)==1)
return true;
else
return false;
}

CTime CTime::operator+(CTime &c)
{
CTime c1;

c1.second=second+c.second;
c1.minute=minute+c.minute;
c1.hour=hour+c.hour;
while(c1.second>59)
{
c1.second=c1.second-60;
c1.minute=c1.minute+1;
}
while(c1.minute>59)
{
c1.minute=c1.minute-60;
c1.hour=c1.hour+1;
}
while(c1.hour >= 24)
c1.hour = c1.hour - 24;
return c1;
}

CTime CTime::operator-(CTime &c)
{
CTime c1;
int h = 0,m = 0,s;

s = c.second + c.minute* 60 + c.hour *3600 - second - minute * 60 - hour * 3600;
if(s < 0)s = -s;
while(s > 59)
{
s = s - 60;
m ++;
}
while(m > 59)
{
m = m - 60;
h ++;
}
while(h >= 24)
h = h - 24;
c1.hour = h;
c1.minute = m;
c1.second = s;

return c1;
}

CTime CTime::operator+(int s)
{
CTime c1;
c1.second = second + s;
c1.hour = hour;
c1.minute = minute;
while(c1.second>59)
{
c1.second = c1.second - 60;
++c1.minute;
}
while(c1.minute>59)
{
c1.minute = c1.minute - 60;
++c1.hour;
}
while(c1.hour >= 24)
c1.hour = c1.hour;
return c1;
}

CTime CTime::operator-(int s)
{
CTime c1;
c1.second = second;
c1.minute = minute;
c1.hour = hour;
while(c1.second<59)
{
c1.second+=60;
--c1.minute;

}
while(c1.minute<0)
{
c1.minute+=60;
--c1.hour;
}
c1.second=second-s;
return c1;
}

CTime CTime::operator++(int)
{
CTime temp(*this);
second++;
while(second>59)
{
second-=60;
++minute;
}
return temp;
}

CTime CTime::operator++()
{
while(++second>59)
{
second-=60;
++minute;
}
return *this;
}

CTime CTime::operator--(int)
{
CTime temp(*this);
second--;
return temp;
}

CTime CTime::operator--()
{
--second;
return *this;
}

CTime CTime::operator+=(CTime &c)
{
CTime c1;

c1.second = second + c.second;
c1.minute = minute + c.minute;
c1.hour = hour + c.hour;
while(c1.second > 59)
{
c1.second = c1.second - 60;
c1.minute ++;
}
while(c1.minute>59)
{
c1.minute=c1.minute-60;
c1.hour ++;
}
while(c1.hour >= 24)
c1.hour = c1.hour - 24;
*this = c1;                                         //问题所在点
return c1;
}

CTime CTime::operator-=(CTime &c)
{
CTime c1;
int h = 0,m = 0,s;

s = c.second + c.minute* 60 + c.hour *3600 - second - minute * 60 - hour * 3600;
if(s < 0)s = -s;
while(s > 59)
{
s = s - 60;
m ++;
}
while(m > 59)
{
m = m - 60;
h ++;
}
while(h >= 24)
h = h - 24;
c1.hour = h;
c1.minute = m;
c1.second = s;
*this = c1;

}

CTime CTime::operator+=(int s)    
{    CTime c1;    
    c1.second = second + s; 
c1.hour = hour;
c1.minute = minute;
    while(c1.second>59)    
    {    
        c1.second = c1.second - 60;    
        ++c1.minute;    
   }    
    while(c1.minute>59)    
    {    
        c1.minute = c1.minute - 60;    
        ++c1.hour;    
   }    
while(c1.hour >= 24)
c1.hour = c1.hour;
*this = c1;
    return c1;   
}    
    
CTime CTime::operator-=(int s)    
{    
     
    CTime c1;   
c1.second = second;
c1.minute = minute;
c1.hour = hour;
    if(c1.second<59)    
    {    
        c1.second+=60;    
        --c1.minute; 

   }    
    if(c1.minute<0)    
    {    
        c1.minute+=60;    
        --c1.hour;    
   }  
    c1.second=second-s; 
*this = c1;
    return c1;      
}  
ostream & operator <<(ostream & output,CTime & c)
{
output<<"("<<c.hour<<":"<<c.minute<<":"<<c.second<<endl;
return output;
}

 istream & operator >>(istream &input,CTime & c)
 {
char d;

cout<<"请输入时间（hh：mm：ss）";
input>>c.hour>>d>>c.minute>>d>>c.second;

return input;
 }

void main()      
{      
    CTime t1(8,20,25), t2(11,20,50), t;      
      
    cout << "t1为："<<t1;           
      
    cout << "t2为："<<t2;      
          
      
    cout << "比较两个时间大小：" << endl;      
      
    if (t1 > t2) cout << "t1 > t2" << endl;      
      
    if (t1 < t2) cout << "t1 < t2" <<endl;      
      
    if (t1 == t2) cout <<"t1 ＝ t2" <<endl;       
      
    if (t1 != t2) cout << "t1 ≠ t2" << endl;      
      
    if (t1 >= t2) cout << "t1 ≥ t2" << endl;      
      
    if (t1 <= t2) cout << "t1 ≤ t2" << endl;      
      
    cout<<endl;     
      
    t = t1 + t2;      
      
    cout << "t1 + t2 = "<<t;      
          
   
    
    t = t1-t2;      
      
    cout << "t1-t2 = "<<t;      
         
    
    t = t1;    
    
    t = t + 35;    
    
    cout<< "t1 + 35 = "<<t;    
           
    
    t = t2;    

    t = t - 8; 

    cout<< "t2 - 8 = "<<t ;    
      
    
    t = t1;    
    
    t = t ++;    
    
    cout << endl;    
    
    cout << "t1++ = "<<t;    
      
    
    t = t1;    
    
    t = ++t;    
    
    cout << "++t1 = "<<t;    
      
    
    t = t2;    
    
    t = t --;    
    
    cout << "t2-- = "<<t;    
     
    
    t = t2;    
    
    t = --t;    
    
    cout << "--t1 = "<<t;    
      
    
    t = t1;  

    t += t2; 

    cout << "t1 += t2,t1 = " << t;    
      
    t = t2;    
    
    t -= t1;    
    
    cout << "t2 -= t1,t2 = "<<t ;    
       
    
    t = t1;    
    
    t += 5;    
    
    cout << "t1 += 5 = "<<t ;    
       
    
    t = t1;    
    
    t -= 6;    
     
    cout << "t1 -= 6 = " <<t;    
      
    
    system("pause");      
}    

问题所在：这是麻烦方法实现的任务二，本应该是上周提出的问题

CTime CTime::operator+=(CTime &c)
{
CTime c1;

c1.second = second + c.second;
c1.minute = minute + c.minute;
c1.hour = hour + c.hour;
while(c1.second > 59)
{
c1.second = c1.second - 60;
c1.minute ++;
}
while(c1.minute>59)
{
c1.minute=c1.minute-60;
c1.hour ++;
}
while(c1.hour >= 24)
c1.hour = c1.hour - 24;
*this = c1;
return c1;
}