C++第二次作业

项目一：

#include <iostream>
using namespace std;
int main()
{
 double m,h,x,a,b;
 cout<<"请输入您的身高（cm):";
 cin>>h;
 cout<<"请输入您的体重(kg):";
 cin>>m;
 x=h-100;
 a=x*1.2;
 b=x*0.8;
    if(m>a)
		cout<<"您已超重，最近吃多了哦！！！"<<endl;
	else
		if(m<b)
			cout<<"您太轻了，平时可以多吃点哦！";
		else
		    cout<<"您的体重很标准，真棒！";
  return 0;
}

项目二：

#include<iostream>
#include<cmath>
using namespace std;
int main()
{ double x,y;
 cout<<"请输入变量x:";
 cin>>x;
  if(x>=1)
  y=x-1;
  else
  y=-x+1; 
 cout<<"输出y="<<y<<endl;
 return 0
}

项目三：

#include<iostream>
#include<cmath>
using namespace std;
int main()
{
   double x1,y1,x2,y2,d;
   cout<<"请输入x1,y1"<<endl;
   cin>>x1>>y1;
   cout<<"请输入x2,y2"<<endl;
   cin>>x2>>y2;
   d=sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));
   cout<<"两点之间的距离d="<<d<<endl;
   return 0;
}