class Solution(object):
def __init__(self):
self.queenList = []
self.result = []
self.charList = []
def solveNQueens(self, n):
for i in range(0,n):
self.charList.append(".")
self.currLayer(0,n)
return self.result
"""
:type n: int
:rtype: List[List[str]]
"""
def currLayer(self, x, n):
if(x==n):
result = []
for queen in self.queenList:
self.charList[queen[1]] = "Q"
result.append("".join(self.charList))
self.charList[queen[1]] = "."
self.result.append(result)
return
for y in range(0,n):
temp = (x,y)
if(self.ableToPutDown(temp)):
self.queenList.append(temp)
self.currLayer(x+1,n)
self.queenList.pop()
def ableToPutDown(self, temp):
for queen in self.queenList:
if( queen[1] == temp[1] ):#same col
return False
elif( abs(queen[0]-temp[0]) == abs(queen[1]-temp[1]) ):#same diagonal
return False
return True
原文：http://my.oschina.net/joshuashaw/blog/503991