2001 计算两点间的距离

#include<iostream>#include<iomanip>#include<cmath>using namespace std;int main(void){    double a,b,c,d;    while(cin>>a>>b>>c>>d)    {        cout<<fixed<<setprecision(2)<<sqrt((c-a)*(c-a)+(d-b)*(d-b))<<endl;    }    return 0;}