蓝桥杯算法提高-能量项链-题解(Java代码)

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Scanner;
public class 能量项链 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] arr = new int[n];
        int[][] a = new int[n][2];
        for (int i = 0; i < n; i++) {
            arr[i] = sc.nextInt();
        }
        for (int i = 0; i < n; i++) {
            a[i][0] = arr[i];
            a[i][1] = arr[(i + 1) % n];
            // System.out.println(a[i][0]+" "+a[i][1]);
        }
        Arrays.sort(arr);
        // System.out.println(Arrays.toString(arr));
        int sum = 0;
        for (int i = 0; i < n - 1; i++) {
            int x = -1, y = -1;
            for (int j = 0; j < n; j++) {
                if (a[j][0] == arr[i] && a[j][0] != -1) {
                    x = j;
                }
                if (a[j][1] == arr[i] && a[j][0] != -1) {
                    y = j;
                }
            }
            //System.out.println((y + 1) + " " + (x + 1));
            sum += a[y][0] * a[y][1] * a[x][1];
            // System.out.println(sum);
            a[x][0] = a[y][0];
            a[y][0] = a[y][1] = -1;
            // for (int j = 0; j < a.length; j++) {
            // System.out.printf("（%d,%d） ",a[j][0],a[j][1]);
            // }
            // System.out.println();
        }
        System.out.println(sum);
    }
}