C++编写选择结构的程序

复制纯文本新窗口

1. #include <iostream>
2. using namespace std;
3. int main( )
4. {
5. int year;
6. bool leap;
7. cout<<"please enter year:";//输出提示
8. cin>>year; //输入年份
9. if (year%4==0) //年份能被4整除
10. {
11. if(year%100==0)//年份能被4整除又能被100整除
12. {
13. if (year%400==0)//年份能被4整除又能被400整除
14. leap=true;//闰年,令leap=true(真)
15. else
16. leap=false;
17. } //非闰年,令leap=false(假)
18. else //年份能被4整除但不能被100整除肯定是闰年
19. leap=true;
20. } //是闰年,令leap=true
21. else //年份不能被4整除肯定不是闰年
22. leap=false; //若为非闰年,令leap=false
23. if (leap)
24. cout<<year<<" is "; //若leap为真,就输出年份和“是”
25. else
26. cout<<year<<" is not ";//若leap为真,就输出年份和“不是”
27. cout<<" a leap year."<<endl; //输出“闰年”
28. return 0;
29. }

#include <iostream>
using namespace std;
int main( )
{
   int year;
   bool leap;
   cout<<"please enter year:";//输出提示
   cin>>year;  //输入年份
   if (year%4==0) //年份能被4整除
   {
      if(year%100==0)//年份能被4整除又能被100整除
      {
         if (year%400==0)//年份能被4整除又能被400整除
            leap=true;//闰年,令leap=true(真)
         else
            leap=false;
      }  //非闰年,令leap=false(假)
      else //年份能被4整除但不能被100整除肯定是闰年
         leap=true;
   }  //是闰年,令leap=true
   else //年份不能被4整除肯定不是闰年
      leap=false;  //若为非闰年,令leap=false
   if (leap)
      cout<<year<<" is "; //若leap为真,就输出年份和“是”
   else
      cout<<year<<" is not ";//若leap为真,就输出年份和“不是”
   cout<<" a leap year."<<endl; //输出“闰年”
   return 0;
}

复制纯文本新窗口

1. #include <iostream>
2. using namespace std;
3. int main( )
4. {
5. int c,s;
6. float p,w,d,f;
7. cout<<"please enter p,w,s:";
8. cin>>p>>w>>s;
9. if(s>=3000)
10. c=12;
11. else
12. c=s/250;
13. switch (c)
14. {
15. case 0:d=0;break;
16. case 1:d=2;break;
17. case 2:
18. case 3:d=5;break;
19. case 4:
20.  
21. case 5:
22. case 6:
23. case 7:d=8;break;
24. case 8:
25. case 9:
26. case 10:
27. case 11:d=10;break;
28. case 12:d=15;break;
29. }
30. f=p*w*s*(1-d/100.0);
31. cout<<"freight="<<f<<endl;
32. return 0;
33. }

#include <iostream>
using namespace std;
int main( )
{
   int c,s;
   float p,w,d,f;
   cout<<"please enter p,w,s:";
   cin>>p>>w>>s;
   if(s>=3000)
      c=12;
   else
      c=s/250;
   switch (c)
   {
      case 0:d=0;break;
      case 1:d=2;break;
      case 2:
      case 3:d=5;break;
      case 4:

      case 5:
      case 6:
      case 7:d=8;break;
      case 8:
      case 9:
      case 10:
      case 11:d=10;break;
      case 12:d=15;break;
   }
   f=p*w*s*(1-d/100.0);
   cout<<"freight="<<f<<endl;
   return 0;
}