第三次上机作业

一：分段函数求值

#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;
}

二：本月有几天？

#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;
	}
}

三：定期存款利息计算器

#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;
}