ZOJ-1730

12345排序为32154，1234排序为2143即符合情况，不一定要完全reverse,因为原数据是一个环

import java.util.Scanner;public class Main{public static void main(String[] args){Scanner sc = new Scanner(System.in);int n = sc.nextInt();for (int i = 0; i < n; i++){int number = sc.nextInt();System.out.println(calc(number));}}static int calc(int number){if (number % 2 == 0)return number / 2 * (number / 2 - 1);elsereturn (number - 1) * (number - 1) / 4;}}