蓝桥杯练习 算法提高 Car的旅行路线 Java

import java.util.Scanner;

public class oiergiv {
    static class City{
        int []x = new int[4];
        int []y = new int[4];
        int price;
        public City(int x1, int y1, int x2, int y2, int x3, int y3, int price) {
            x[0] = x1;
            y[0] = y1;
            x[1] = x2;
            y[1] = y2;
            x[2] = x3;
            y[2] = y3;
            double t12 = distance(x1,y1,x2,y2);
            double t13 = distance(x1,y1,x3,y3);
            double t23 = distance(x2,y2,x3,y3);
            //计算另一个机场的坐标
            if(Math.abs(t12*t12+t13*t13-t23*t23)<0.000001){
                x[3] = x2+x3-x1;
                y[3] = y2+y3-y1;
            }
            if(Math.abs(t12*t12+t23*t23-t13*t13)<0.000001){
                x[3] = x1+x3-x2;
                y[3] = y1+y3-y2;
            }
            if(Math.abs(t13*t13+t23*t23-t12*t12)<0.000001){
                x[3] = x1+x2-x3;
                y[3] = y1+y2-y3;
            }
            this.price = price;
        }
        //计算机场之间的距离
        private double distance(int x12, int y12, int x22, int y22) {
            return Math.sqrt((x22-x12)*(x22-x12)+(y22-y12)*(y22-y12));
        }
    }
    static int s,t,A,B;
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        s = sc.nextInt();
        t = sc.nextInt();
        A = sc.nextInt();
        B = sc.nextInt();
        double[][] price = new double[s*4][s*4];//机场图(所有机场都联通，不用赋INF)
        City []cities = new City[s];//城市数组
        for (int i = 0; i < s; i++) {//下标0-1-2对应1-2-3城市编号
            int x1 = sc.nextInt();
            int y1 = sc.nextInt();
            int x2 = sc.nextInt();
            int y2 = sc.nextInt();
            int x3 = sc.nextInt();
            int y3 = sc.nextInt();
            int train_price = sc.nextInt();
            City citys = new City(x1, y1, x2, y2, x3, y3, train_price);
            cities[i] = citys;//将每个城市封装为一个对象
        }
        //邻接矩阵存机场图,价格是权值
        for(int i = 0;i < s*4;i++){
            for(int j = 0;j < s*4;j++){
                if(i/4 == j/4){//如果是同城的机场，×的是高铁价格
                    price[i][j] = dist(cities[i/4].x[i%4],cities[i/4].y[i%4],cities[j/4].x[j%4],cities[j/4].y[j%4])*cities[i/4].price;
                }else{//如果是不同城的机场，×的是飞机价格
                    price[i][j] = dist(cities[i/4].x[i%4],cities[i/4].y[i%4],cities[j/4].x[j%4],cities[j/4].y[j%4])*t;
                }
            }
        }
        floyd(price);
        //最后还要找出最小值，因为是飞两座城市之间的最小价格，而不是机场之间
        double min = price[(A-1)*4][(B-1)*4];
        for(int i = (A-1)*4; i < A*4; i++){
            for(int j = (B-1)*4; j < B*4; j++){
                min = Math.min(price[i][j],min);
            }
        }
        System.out.printf("%.1f", min);
    }
    public static void floyd(double[][] price){
        //floyd的三段for
        for (int k = 0; k < s*4; k++) {
            for (int i = 0; i < s*4; i++) {
                for (int j = 0; j < s*4; j++) {
                    price[i][j] = Math.min(price[i][j], price[i][k] + price[k][j]);
                }
            }
        }
    }
    //计算机场之间的距离,计算价格
    private static double dist(int x12, int y12, int x22, int y22) {
        return Math.sqrt((x22-x12)*(x22-x12)+(y22-y12)*(y22-y12));
    }
}