LeetCode OJ：Spiral MatrixII（螺旋矩阵II）

Given an integer n, generate a square matrix filled with elements from 1 to n2 in spiral order.

For example,
Given n = 3,

You should return the following matrix:

[
 [ 1, 2, 3 ],
 [ 8, 9, 4 ],
 [ 7, 6, 5 ]
]

依旧是dfs问题，代码如下所示：

 class Solution {
 public:
     vector<vector<int>> generateMatrix(int n) {
         vector<vector<int>>ret(n, vector<int>(n, ));
         vector<vector<bool>>mark(n, vector<bool>(n,false));
         if(!n) return ret;
         dfs(ret, mark, , -, n, , );
         return ret;
     }

     void dfs(vector<vector<int>> & ret, vector<vector<bool>> & mark, int i, int j, int n, int curr, int currVal)
     {
         for(int k = ; k < ; ++k){
             int dirct = (curr + k) % ;
             int ii = i + drct[dirct][];
             int jj = j + drct[dirct][];
             if(ii >=  && ii < n &&
                 jj >=  && jj < n &&
                 mark[ii][jj] == false){
                 mark[ii][jj] = true;
                 ret[ii][jj] = currVal;
                 dfs(ret, mark, ii, jj, n, dirct, currVal + );
             }

         }
     }   

 private:
     vector<vector<int>>drct = {{,},{,},{,-},{-,}};
 };

代码写的比较乱，凑合着看哈哈