Leetcode 59 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 ]
]

方阵蛇形填数
和上一道蛇形取数差不多。

http://blog.csdn.net/accepthjp/article/details/52577112

class Solution {
public:
vector<vector<int>> generateMatrix(int n) {
vector<int> row(n,0);
vector<vector<int>> result(n,row);
int rows=n,cols=n,cnt=0;
for(int x=0,y=0;x<rows && y<cols;x++,y++)
{
for(int i=y;i<cols;i++) result[x][i]=++cnt;
for(int i=x+1;i<rows;i++) result[i][cols-1]=++cnt;
for(int i=cols-2;i>=y;i--) result[rows-1][i]=++cnt;
for(int i=rows-2;i>x;i--) result[i][y]=++cnt;
rows--;
cols--;
}
return result;
}
};