题解 | 点到直线距离

#include <bits/stdc++.h>
using namespace std;

struct point{
    double x,y;
    point(double A,double B){
        x=A,y=B;
    }
    point() = default;
};

struct line{
    point point_A,point_B;
    line(point A,point B){
        point_A = A,point_B = B;
    }
    line() = default;
};

double getDistance(point P, line L){
    // TODO: 计算点P到直线L的距离
    double A=L.point_B.y-L.point_A.y;
    double B=L.point_A.x-L.point_B.x;
	double C=L.point_A.y*L.point_B.x-L.point_A.x*L.point_B.y;
	
	double d=fabs(A*P.x+B*P.y+C)/sqrt(A*A+B*B);
	
	return d; 
}

int main(){
	
	double a,b,x1,y1,x2,y2;
	
	cin>>a>>b>>x1>>y1>>x2>>y2;
	
	point po=point(a,b);
	point po1=point(x1,y1);
	point po2=point(x2,y2);
	line li=line(po1,po2);
	
	cout<<fixed<<setprecision(2)<<getDistance(po,li)<<endl;
}