C++作业2

#include<iostream>
using namespace std;
int main()
{
int x,y;
cout<<"请输入一个整数："<<endl;
cin>>x;
if(x>=1)
{
y=x-1;
cout<<"x-1="<<y<<endl;
}
else
{
if(x<1)
y=-x+1;
cout<<"-x+1="<<y<<endl;
}
return 0;
}

#include<iostream>
#include<cmath>
using namespace std;
int main()
{
double x1,x2,y1,y2,s,m;
cout<<"请依次输入x1，x2，y1，y2的值："<<endl;
cin>>x1>>x2>>y1>>y2;
s=(x1-x2)*(x1-x2)+(y1-y2)*(y1-y2);
m=sqrt(s);
cout<<m<<endl;
return 0;
}

#include<iostream>
using namespace std;
int main()
{
cout<<"机智银行欢迎您"<<endl;
int a,b;
cout<<"请输入密码"<<endl;
cin>>a;
if(a!=980311)
cout<<"密码输入错误"<<endl;
else
{
cout<<"1.查询\n2.取款\n3.存款\n4.转帐\n0.退出"<<endl;
cin>>b;
if(b==1)
cout<<"谢谢，您选择了1号功能"<<endl;
else if(b==2)
cout<<"谢谢，您选择了2号功能"<<endl;
else if(b==3)
cout<<"谢谢，您选择了3号功能"<<endl;
else if(b==4)
cout<<"谢谢，您选择了4号功能"<<endl;
else if(b==0)
cout<<"谢谢，您选择了0号功能"<<endl;
else
cout<<"输入错误"<<endl;
}
return 0;
}