c++作业03

#include<iostream>
using namespace std;
int main()
{
int year,month,day;
cout<<"欢迎查询本月天数"<<endl;
cout<<"请输入年份";
cin>>year;
cout<<"请输入月份";
cin>>month;
switch(month)
{
case 1:   day=31;break;
case 3:   day=31;break;
case 4:   day=30;break;
case 5:   day=31;break;
case 6:   day=30;break;
case 7:   day=31;break;
case 8:   day=31;break;
case 9:   day=30;break;
case 10:   day=31;break;
case 11:   day=30;break;
case 12:   day=30;break;
case 2:    if( (year%4==0 && year%100!=0)|| year%400==0 )
day=29;
else day=28;break;
default : cout<<"Error"<<endl;
}
cout<<"本月"<<day<<"天"<<endl;
return 0;
}

#include <iostream>
using namespace std;
int main( )
{
double money,rate=0,time=0,p;
cout<<"欢迎使用利息计算器！\n 请输入存款金额：";
cin>>money;
cout<<"======存款期限======"<<endl;
cout<<" 1. 3个月\n 2. 6个月\n 3. 一年\n 4. 两年\n 5. 三年\n 6. 五年\n 请输入存款期限的代号：";
int n;
cin>>n;
switch(n)
{
case 1:time=0.25,rate=0.031;break;
case 2:time=0.5,rate=0.033;break;
case 3:time=1,rate=0.035;break;
case 4:time=2,rate=0.044;break;
case 5:time=3,rate=0.050;break;
case 6:time=5,rate=0.055;break;
}
p=money*rate*time;
cout<<"到期利息为："<<p<<"元\n 本息合计共："<<money+p<<"元"<<endl;
cout<<"感谢您的使用，欢迎下次光临"<<endl;
return 0;
}

#include<iostream>
#include<cmath>
using namespace std;
int main()
{
float x,y;
cout<<"请输入x的值"<<endl;
cin>>x;
if(x<2)  y=x;
else if(x<6)  y=x*x+1;
else if(x<10)  y=sqrt(x+1);
else y=1/(x+1);
cout<<"分段函数y的值为:"<<y<<endl;
return 0;
}