第三次上机作业

#include <iostream>
#include <cmath>
using namespace std;
void main()
{
double x,y;
cout<<"输入x:";
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<<"y="<<y<<endl;
}

#include <iostream>
using namespace std;
void main()
{
int year,month;
cin>>year>>month;
if(year%4==0)
{
if(year%10!=0||year%400==0)
{
cout<<year<<"年是闰年"<<endl;
if(month==2)
cout<<month<<"月有28天"<<endl;
else if(month==1||3||5||7||8||10||12)
cout<<month<<"月有31天"<<endl;
else
cout<<month<<"月有30天"<<endl;
}
}
else
{
cout<<year<<"年不是闰年"<<endl;
if(month==2)
cout<<month<<"月有29天"<<endl;
else if(month==1||3||5||7||8||10||12)
cout<<month<<"月有31天"<<endl;
else
cout<<month<<"月有30天"<<endl;
}
}

#include <iostream>
using namespace std;
void main()
{
double CK,LX1,LX2,LX3,LX4,LX5,LX6;
int a;
cout<<"欢迎使用利息计算器！"<<endl;
cout<<"请输入存款金额:";
cin>>CK;
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"<<endl;
cout<<"请选择存款期限的代号：";
cin>>a;
LX1=CK*0.031*0.25;
LX2=CK*0.033*0.5;
LX3=CK*0.035*1;
LX4=CK*0.044*2;
LX5=CK*0.050*3;
LX6=CK*0.055*5;
switch(a)
{
case 1:cout<<"到期利息为;"<<LX1<<"元,"<<"本息合计为："<<LX1+CK<<"元"<<"\n"; break;
case 2:cout<<"到期利息为;"<<LX2<<"元,"<<"本息合计为："<<LX2+CK<<"元"<<"\n"; break;
case 3:cout<<"到期利息为;"<<LX3<<"元,"<<"本息合计为："<<LX3+CK<<"元"<<"\n"; break;
case 4:cout<<"到期利息为;"<<LX4<<"元,"<<"本息合计为："<<LX4+CK<<"元"<<"\n"; break;
case 5:cout<<"到期利息为;"<<LX5<<"元,"<<"本息合计为："<<LX5+CK<<"元"<<"\n"; break;
case 6:cout<<"到期利息为;"<<LX6<<"元,"<<"本息合计为："<<LX6+CK<<"元"<<"\n"; break;
}
cout<<"感谢您的使用，欢迎下次光临！"<<endl;
}