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