C++语言程序设计第四版（郑莉）课后题

2-26

#include 
using namespace std;
char flag;
char Israiny(char flag)
{if (flag=='Y')
{cout<<"下雨";}
else if (flag=='N')
{cout<<"没下";}}
int main()
{cout<<"下雨了么";
char a;
cin>>a;
do 
{cout<<"下雨了么";
cin>>a;}
while(a!='Y' and a!='N');
if(a=='Y' or a=='N')
{Israiny(a);}}

2-27

#include 
using namespace std;
int main()
{
    cout<<"考了多少分";
    int grade;
    cin>>grade;
    if(grade<=100 and grade >=90)
    {
        cout<<"忧";
    }
    else if(grade<90 and grade >=80)
        {
        cout<<"良";
    }
     else if(grade<80 and grade >=60)
        {
        cout<<"中";
    }
    else
    {
        cout<<"差";
    }
}

2-28
（1）if …else…

#include 
using namespace std;
int main()
{
cout<<"Menu:A,D,S,Q, select one:"
char a;
cin>>a;
do
{{if (a=='A')
{cout<<"添加";}
else if (a=='D')
{cout<<"删除";}
else if (a=='S')
{cout<<"排序";}}
cin>>a;
while (a!='Q');
if (a=='Q')
{cout<<"结束程序";}
}

(2)switch语句

#include 
using namespace std;
int main()
{cout<<"Menu:A,D,S,Q,select one:";
char a ;
cin a;
do{
switch(a)
{case 'A':
{cout<<"添加";
cin>>a;
break;}
case 'D':
{cout<<"删除";
cin>>a;
break;}
case 'S':
{cout<<"排序";
cin>>a;
break;}
}
}
while(a!=Q);
if(a=='Q')
{cout<<"程序结束";}}

2-29

#include 
using namespace std;
int number;
bool Is_Prime_Number(int number)
{
    int j;
    for (j=2;j

2-31

#include 
using namespace std;
int main()
{
struct time{int year;
int month;
int day;
int time;
    int year;}Time1;
    cout<<"input year,month,day,time:";
        int i;
for(i=1;i<4;i++)
{
if(i==1)
{
cin>>Time1.year;
cout<>Time1.month;
cout<>Time1.day;
cout<>Time1.time;
cout<

2-32

#include 
  using namespace std; 
 int main()
 {     int number =50;     
       int i;   
   do     
    {    cin>>i; 
   {  if(i>number) 
   {cout<<"i>number";  }
    else if(i

2-34

#include 
using namespace std;
int main()
{
int i,j,k;
int sum;
sum=0;
for(i=1;i<5;i++)
for(j=1;j<5;j++)
for(k=1;k<5;k++)
{
if(i!=j && j!=k &&i!=k)
{sum=sum+1;}
}
cout<

2-35

#include 
using namespace std;
int main()
{
int i,j,k;
for(i=1;i<=9;i++)
{for(j=1;j<=i;j++)
{x=i*j;
cout<