问题:N皇后问题,给定一个正整数n,输出在n*n的方格中所有的皇后问题的解决办法
示例:
python代码:
class Solution(object): def solveNQueens(self, n): """ :type n: int :rtype: List[List[str]] """ if not n: return [] elif n == 1: return [["Q"]] else: self.out = [] self.Queen(n) return self.out def Queen(self,n,row=0,ele=[],col_use=[],dia_l=[],dia_r=[]): if row == n: self.out.append(ele) return for col in range(n): flag = False if col in col_use or (col+row) in dia_l or (col-row) in dia_r: continue else: flag = True self.Queen(n,row+1,ele+["."*col+"Q"+(n-col-1)*"."],col_use+[col],dia_l+[col+row],dia_r+[col-row]) if not flag: return