【leetcode】Spiral Matrix II

Spiral Matrix 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 ]
]

 

与Spiral Matrix类似：

 

 class Solution {
 public:
     vector<vector<int> > generateMatrix(int n) {

         int x1=;
         int y1=;
         int x2=n-;
         int y2=n-;

         int count=;
         vector<vector<int>> result(n,vector<int>(n));
         while(count<n*n)
         {

             for(int j=y1;j<=y2;j++)
             {
                 count++;
                 result[x1][j]=count;
             }
             for(int i=x1+;i<=x2;i++)
             {
                 count++;
                 result[i][y2]=count;
             }

             for(int j=y2-;j>=y1;j--)
             {
                 count++;
                 result[x2][j]=count;
             }

             for(int i=x2-;i>x1;i--)
             {
                 count++;
                 result[i][x1]=count;
             }

             x1++;y1++;x2--;y2--;
         }

         return result;

     }
 };