# # # @param n int整型 the n # @return int整型 # class Solution: def Nqueen(self , n ): num = [0 for i in range(n)] res = [0] mark = {} self.dfs(num,0,mark,res) return res[0] def dfs(self,num,i,mark,res): if i==len(num): res[0] += 1 return for j in range(len(num)): num[i] = j if self.valid(num,i,mark): ...