CSP 202009-1 称检测点查询（Java）

题目链接：

计算机软件能力认证考试系统http://118.190.20.162/view.page?gpid=T113

【分析】计算距离，然后用一个Pair存储，按照要求排序即可。

import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;
import java.util.Scanner;

public class Main {

    public static class Pair{
        int d;
        int i;
        public Pair(int d, int i){
            this.d = d;
            this.i = i;
        }
    }

    static class cmp implements Comparator {
        @Override
        public int compare(Pair o1, Pair o2){
            if(o1.d < o2.d || (o1.d == o2.d && o1.i < o2.i)) return -1;
            return 1;
        }
    }

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n, x, y, a, b;
        n = scanner.nextInt();
        x = scanner.nextInt();
        y = scanner.nextInt();
        int i, j;
        List list = new ArrayList<>();
        for(i = 0; i < n; i++){
            a = scanner.nextInt();
            b = scanner.nextInt();
            list.add(new Pair((a - x) * (a - x) + (b - y) * (b - y), i + 1));
        }
        list.sort(new cmp());
//        for(Pair pair: list){
//            System.out.print(pair.i);
//            System.out.print(" ");
//            System.out.print(pair.d);
//            System.out.println();
//        }
        for(i = 0; i < 3; i++){
            System.out.println(list.get(i).i);
        }
    }

}