c++作业2

#include <iostream>
int main ()
{
int a,b;
cout<<"     银行欢迎您"<<endl;
cout<<"请输入密码：";
cin>>a;
if(a==1501901011)
{
cout<<"1.查询"<<"2.取款"<<"3.存款"<<"4.转账"<<"0.退出"<<endl;
cin>>b;
if(b==1)
cout<<"谢谢，您选择了1号功能";
else if(b==2)
cout<<"谢谢，您选择了2号功能";
else if(b==3)
cout<<"谢谢，您选择了3号功能";
else if(b==4)
cout<<"谢谢，您选择了4号功能";
else if(b==0)
cout<<"谢谢，您选择了0号功能";
}
else
cout<<"对不起，您输入的密码错误，请重试！";
return 0;
}

#include <iostream>
#include <cmath>
using namespace std;
int main ()
{
double x1,y1,x2,y2,d;
cout<<"请输入第一个点的坐标x1,y1";
cin>>x1>>y1;
cout<<"请输入第二个点的坐标x2,y2";
cin>>x2>>y2;
d=sqrt((x2-x1)*(x2-x1)+(y2-y1)*(y2-y1));
cout<<"两点间的距离为"<<d;
return 0;
}

#include<iostream>
using namespace std;
int main()
{
int x,y;
cout<<"x=";
cin>>x;
if(x>=1) y=x-1;
else     y=-x+1;
cout<<y<<endl;
return 0;
}