又是一个八皇后问题：
Given an integer n, return all distinct solutions to the n-queens puzzle.
Each solution contains a distinct board configuration of the n-queens' placement, where 'Q' and '.' both indicate a queen and an empty space respectively.
For example,
There exist two distinct solutions to the 4-queens puzzle:
[ [".Q..", // Solution 1 "...Q", "Q...", "..Q."], ["..Q.", // Solution 2 "Q...", "...Q", ".Q.."] ]
class Solution {
public:
vector
> solveNQueens(int n) {
this->N=n;
memset(matrix,0,sizeof(matrix));
dfs(0);
return d;
}
int check(int x,int y)
{
for(int j=0;j
mt; for(int i=0;i
> d; int matrix[100][100]; };