题解 | 点到直线距离

#include <bits/stdc++.h>
#include <cmath>
#include <math.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_B.x*L.point_A.y-
           L.point_A.x*L.point_B.y;
       double fenzi=fabs(P.x*A+P.y*B+C);
       double fenmu=sqrt(pow(A,2)+pow(B,2));
       return fenmu==0?0:fenzi/fenmu;
}


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;
}