/*
 *Author:Junyi Sun @CCNU
* E-mail:fxsjy@yahoo.com.cn
*/

using System;
namespace sunjoy
{
    public class Queen
    {
        public static int Main()
        {
            int board_size = 0,x=0,y=0;//棋盘大小,当前行,当前列
            uint solution_count = 0;   //皇后摆放方案的个数
            int[] rows, cols, slot1, slot2, x2y;//行占用情况，列占用情况，“/”状斜线占用情况，“\”状斜线占用情况，皇后坐标
            DateTime t_start, t_end;
           
            Console.WriteLine("请输入棋盘的大小");
            try
            {
                board_size = Convert.ToInt32(Console.ReadLine());
                if (board_size <= 0)
                {
                    Console.WriteLine("非法数据");
                    return -1;
                }
            }
            catch (Exception e) { Console.WriteLine("发生异常" + e.Message); };

            rows = new int[board_size];
            cols = new int[board_size];
            slot1 = new int[board_size * 2 - 1];
            slot2 = new int[board_size * 2 - 1];
            x2y = new int[board_size];

            for (int i = 0; i < board_size; i++)
                x2y[i] = -1;   //坐标初始化都为-1
            t_start = DateTime.Now;
            while (true)
            {
                for (y = x2y[x]+1; y < board_size; y++)
                    if (rows[x] == 0 && cols[y] == 0 && slot1[x + y] == 0 && slot2[x - y + board_size - 1] == 0)
                        break;

                if (y < board_size)
                {
                    //第X行的棋子落下