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 chang(point A,point B){
    double a1;
    a1=sqrt(pow(A.x-B.x,2)+pow(A.y-B.y,2));
    return a1;
}
double getDistance(point P, line L){
    // TODO: 计算点P到直线L的距离
    double b1,b2,b3;
    b1=chang(P,L.point_A);
    b2=chang(P,L.point_B);
    b3=chang(L.point_B,L.point_A);
    double M=(b1+b2+b3)/2;
    double N;
    N=sqrt(M*(M-b1)*(M-b2)*(M-b3));
    return N*2/b3;
    

}















































































































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;
}