Spiral Matrix II @LeetCode

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 ]
]

	package leetcode;
	import java.util.Arrays;
	/**
	* Solution: similar to Spiral Matrix I. even simplier because of square
	* don't forget to return null when n < 0
	*
	* Refactor:
	* int[level][i] = count; count++; --> int[level][i] = count++;
	*
	* @author jeffwan
	* @date Apr 2, 2014
	*/
	public class GenerateMatrix {
	public int[][] generateMatrix(int n) {
	if (n < 0) {
	return null;
	}
	int[][] result = new int[n][n];
	int level = 0;
	int count = 1;
	while (level * 2 < n) {
	for (int i = level; i < n - level; i++) {
	result[level][i] = count++;
	}
	for (int i = level + 1; i < n - level; i++) {
	result[i][n - level - 1] = count++;
	}
	if (n - level * 2 == 1) {
	break;
	}
	for (int i = n - level - 2; i >= level; i--) {
	result[n - level - 1][i] = count++;
	}
	for (int i = n - level - 2; i >= level + 1; i--) {
	result[i][level] = count++;
	}
	level++;
	}
	return result;
	}
	}

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