题解 | 绕距

#include <cmath>
#include <iomanip>
#include <iostream>
using namespace std;

int main(){
    double xx1,xx2,yy1,yy2;
    double de,dm,derta;
    cin>>xx1>>yy1>>xx2>>yy2;
    w=(xx1-xx2)*(xx1-xx2)+(yy1-yy2)*(yy1-yy2);
    dm=sqrt((xx1-xx2)*(xx1-xx2)+(yy1-yy2)*(yy1-yy2));
    de=fabs(xx1-xx2)+fabs(yy1-yy2);
derta=fabs(Dm-De);
cout<<fixed<<setprecision(6)<<derta<<endl;
return 0;
}