c++作業3

項目2：本月有幾天？

代碼：

#include <iostream>     
using namespace std;  
int main()
{
	int year,month,hun,four,rn,fh;
	cout<<"請輸入年和月:";
	cin>>year>>month;
	hun=year%100;
	fh=year%400;
	four=year%4;
	if(hun==0)
	{
		if(fh==0)
			rn=1;
		else
			rn=0;
	}
	else
	{
		if(four==0)
			rn=1;
		else
			rn=0;
	}
	if(rn==1)
	{
		switch(month)
		{
		case 1:
		case 3:
		case 5:
		case 7:
		case 8:
		case 10:
		case 12:cout<<"該月有31天\n";break;
		case 2:cout<<"該月有29天\n";break;
		case 4:
		case 6:
		case 9:
		case 11:cout<<"該月有30天\n";break;
		}
	}
	else
	{
		switch(month)
		{
		case 1:
		case 3:
		case 5:
		case 7:
		case 8:
		case 10:
		case 12:cout<<"該月有31天\n";break;
		case 2:cout<<"該月有28天\n";break;
		case 4:
		case 6:
		case 9:
		case 11:cout<<"該月有30天\n";break;
		}
	}
	return 0;
}

項目3：定期存款利息計算器

#include<iostream>
using namespace std;
int main()
{
    double lx,money,sum;
    int m;
    char choose;
    m=1;
    cout<<"歡迎使用利息計算器\n";
    cout<<"請輸入存款金額：";cin>>money;
    cout<<"========存款期限========\n";
    cout<<"1. 3個月\n2. 6個月\n3. 一年\n4. 兩年\n5. 三年\n6. 五年\n請輸入存款期限的代號:";
    cin>>choose;
    switch(choose)
    {
        case '1':lx=money*0.031*0.25;break;
        case '2':lx=money*0.033*0.5;break;
        case '3':lx=money*1*0.035;break;
        case '4':lx=money*2*0.044;break;
        case '5':lx=money*3*0.05;break;
        case '6':lx=money*5*0.055;break;
        default:m=0;
    }
    sum=money+lx;
    if(m=0)
        cout<<"輸入錯誤\n";
    else
        cout<<"到期利息爲"<<lx<<"元，本息合計共"<<sum<<"元\n";

    return 0;
}

項目4：多分數段函數求值

#include<iostream>
#include<cmath>
using namespace std;
int main()
{
    int x,m;
    double y;
    cout<<"請輸入X:";cin>>x;
    m=(x<2)+(x<6)+(x<10);
    switch(m)
    {
        case 1:y=x;break;
        case 2:y=x*x+1;break;
        case 3:y=sqrt(x+1);break;
        default:y=1.0/(x+1);break;
    }
    cout<<"y="<<y<<"\n";
    return 0;
}