Ｃ＋＋作业３

#include <iostream>
using namespace std;
int main( )
{
double dSalary,dTax=0,dNetIncome=0,dValue;
cout<<"请输入您本月的收入总额（元）：";
cin>>dSalary;// 下面求解应缴个人所和税dTax和税后收入dNetIncome
dValue=dSalary-3500;
if(dValue<=0) dTax=0.0;
else if(0<dValue&&dValue<=1500) dTax=dValue*0.03-0.0;
else if(dValue<=4500)dTax=dValue*0.10-105.0;
else if(dValue<=9000)dTax=dValue*0.20-555.0;
else if(dValue<=35000)dTax=dValue*0.25-1005.0;
else if(dValue<=55000)dTax=dValue*0.30-2755.0;
else if(dValue<=80000)dTax=dValue*0.35-5505.0;
else if(dValue>80000)dTax=dValue*0.45-13505.0;
dNetIncome=dSalary-dTax;
cout<<"您本月应缴个人所和税 "<<dTax<<" 元，税后收入是 "<<dNetIncome<<" 元。\n";
cout<<"依法纳税，共享繁荣。谢谢使用！\n";
return 0;
}

#include <iostream.h>
void main()
{
double money,interest,all;
int code;
cout<<"欢迎使用利息计算器!"<<endl;
cout<<"请输入存款金额：";
cin>>money;
cout<<"==========存款期限=========="<<endl;
cout<<"1. 3个月\n2. 6个月\n3. 一年\n4. 二年\n5. 三年\n6. 五年 "<<endl;
cout<<"请输入存款期限的代号：";
cin>>code;
switch(code)
{
case 1:
{
interest=money*0.031*0.250;
all=interest+money;
break;
}
case 2:
{
interest=money*0.033*0.5;
all=interest+money;
break;

}
case 3:
{
interest=money*0.035*1;
all=interest+money;
break;
}
case 4:
{
interest=money*0.044*2;
all=interest+money;
break;
}
case 5:
{
interest=money*0.05*3;
all=interest+money;
break;
}
case 6:
{
interest=money*0.055*5;
all=interest+money;
break;
}
}
cout<<"到期利息为："<<interest<<"元,"<<"本息合计共计"<<all<<"元"<<endl;
cout<<"感谢您的使用，欢迎下次光临！"<<endl;

}

#include <iostream.h>
#include <cmath>
void main()
{
double x,y;
cout<<"请输入x的值：";
cin>>x;

if (x<2) y=x;
else if (x<6) y=x*x+1;
else if (x<10) y=sqrt(x+1);
else if (x>=10) y=1/(x+1);
cout<<"y="<<y<<endl;
}