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 t1=sqrt(pow((L.point_A.x-P.x),2)+pow((L.point_A.y-P.y),2));
    double t2=sqrt(pow((L.point_B.x-P.x),2)+pow((L.point_B.y-P.y),2));
    double t3=sqrt(pow((L.point_A.x-L.point_B.x),2)+pow((L.point_A.y-L.point_B.y),2));
    double s = (t1 + t2 + t3) / 2;
    double area = sqrt(s * (s - t1) * (s - t2) * (s - t3));
    double res = 2 * area / t3;
    return res;
}















































































































int main(){
    int a, b, sx, sy, tx, ty;
    cin >> a >> b >> sx >> sy >> tx >> ty;
    point A(sx, sy), B(tx, ty), C(a, b);
    line L(A, B);
    printf("%.2lf", getDistance(C, L));
    return 0;
}