leetcode之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 ]
]
这道题和上一道题几乎完全相同，只是注意当n=1的情况
下面附上代码，哎刚做了上一题，这道题居然也能做个40分钟，只能说明效率太低，不注意细节了

public class Solution {
    public int[][] generateMatrix(int n) {
        int number = n*n;
		int count = 0;
		int[][] matrixResult = new int[n][n];
		int rowNumber = 0;
		int columnNumber = 0;
		while(n>0){
		    if(n==1){
		    matrixResult[rowNumber][columnNumber] = ++count;
		}
			for(int i =0;i<n-1;i++){
				matrixResult[rowNumber][columnNumber++] = ++count;
			}
			for(int i = 0;i<n-1;i++){
				matrixResult[rowNumber++][columnNumber]= ++count;
			}
			for(int i = 0;i<n-1;i++){
				matrixResult[rowNumber][columnNumber--]= ++count;
			}
			for(int i = 0;i<n-1;i++){
			    matrixResult[rowNumber--][columnNumber]= ++count;
			}
			rowNumber++;
			columnNumber++;
			n = n -2;
		}
		return matrixResult;
    }
}