题解 | 牛牛与切割机-Java

问题可等价为：周长相等，求最小面积，则“越长方形面积越小”

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        long[] arr = new long[n];
        long count = 0;
        for (int i = 0; i < n; i++) {
            arr[i] = in.nextInt();
            count += arr[i];
        }
        if (arr[0] >= arr[n - 1]) System.out.println(arr[n - 1] * (count - arr[n - 1]));
        else System.out.println(arr[0] * (count - arr[0]));
    }
}