# -*- coding: utf-8 -*-




import numpy as np


def printP():
    global n
    global pieces
    for i in range(n):
        for j in range(n):
            print "%d\t"%pieces[i][j],
        print ""


def init():
    '''
    初始化棋盘
    '''
    global n
    global pieces
    global point #用于记录剩余的点
    pieces = [([0]*100)for j in range(100)]
    pieces = np.array(pieces)
    
    point = []
    for i in range(n):
        for j in range(n):
            point.append((i,j))


def checkXY(x,y):
    '''
    检查点（x,y）是否在棋盘上
    '''
    global n
    if x>=0 and x<n and y>=0 and y<n:
        return True
    return False
    
    
def out1(x,y):
    '''
    找出所有方向（包括已经被走过的点）
    '''
    global n
    global pieces
    global direction
    outLine1 = []
    for i in range(8):
        x1 = x+direction[i][0]
        y1 = y+direction[i][1]
        if checkXY(x1,y1):
            outLine1.append((x1,y1))
    return outLine1


def out(x,y):
    '''
    找出所有可能走的路径
    '''
    outLine1 = out1(x,y)
    outLine = []
    for item in outLine1:
        if pieces[item[0]][item[1]]==0:
            outLine.append(item)
    return outLine


def check1():
    '''
    剪枝1： 判断初始点各个方向上的点是否已经全走过
    '''
    global point
    global direction
    global x0
    global y0
    
    for i in range(8):
        x1 = x0+direction[i][0]
        y1 = y0+direction[i][1]
        if checkXY(x1,y1):
            if (x1,y1) in point:
                return True
    return False


def check2(x,y):
    '''
    判断剩余点中是否存在孤立点
    '''
    global point
    
    for p in point:
        if p[0]==x and p[1]==y:
            continue
        if len(out(p[0],p[1]))<1:
            return True
    return True
    
    
    
def play(x,y,k):
    global n
    global x0,y0
    global succ
    global point
    
    pieces[x][y] = k
    
    point.remove((x,y))


    if k==n*n:#找到一条巡游路径
        if (x0,y0) in out1(x,y):#判断能否回到初始点
            succ = True
        return
   
    k += 1
    outLine = out(x,y)
    l = len(outLine)
    if l == 0:#该点没有出路回溯
        return
    else:
        outDic=dict()
        for item in outLine:
            outDic[item] = len(out(item[0],item[1]))
        #按出路从小到达排序
        outDic = sorted(outDic.iteritems(),key=lambda d:d[1], reverse = False)
        
        for item in outDic:
            if check1()==False:
                continue
            if check2(x,y)==False:
                continue
            play(item[0][0],item[0][1],k)
            if succ:#如果已经找到则跳出循环
                break
            pieces[item[0][0],item[0][1]]=0#还原步骤，继续搜索
            point.append((item[0][0],item[0][1]))
        return#搜索不到则回溯


if __name__=="__main__":
    pieces = []#记录巡游顺序
    point = []#记录剩余的点
    direction = [(2,1),(2,-1),(-2,1),(-2,-1),(1,2),(1,-2),(-1,2),(-1,-2)]#八个方向
    succ = False
    
    n = 8 #棋盘维n*n维
    
    #起始点
    x0 = 1
    y0 = 1
    
    '''
    #控制台输入
    while checkXY(x0,y0)==False:
        print "左上角坐标为（0,0）"
        n = int(raw_input("n:").strip())
        x0 = int(raw_input("x0:").strip())
        y0 = int(raw_input("y0:").strip())
    '''
    print "n:",n
    print "起始点:(%d,%d)\n"%(x0,y0)
    init()#初始化
    play(x0,y0,1)#开始巡游
    
    if succ:
        print "找到一条巡游路径"
        printP()
    else:
        print "不存在巡游路径"