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 ]
]

类似题目 ：Spiral Matrix
 1 public class Solution {
 2     public int[][] generateMatrix(int n) {
 3         int[][] result = new int[n][n];
 4         if (n <= 0) {
 5             return result;
 6         }
 7         int xStart = 0;
 8         int yStart = 0;
 9         int num = 1;
10         while (n > 0) {
11             if (n == 1) {
12                 result[yStart][xStart] = num;
13             }
14             
15             for (int i = 0; i < n - 1; i++) {
16                 result[yStart][xStart + i] = num++;
17             }
18             for (int i = 0; i < n - 1; i++) {
19                 result[yStart + i][xStart + n - 1] = num++;
20             }
21             for (int i = 0; i < n - 1; i++) {
22                 result[yStart + n - 1][xStart + n - 1 - i] = num++;
23             }
24             for (int i = 0; i < n - 1; i++) {
25                 result[yStart + n - 1 - i][xStart] = num++;
26             }
27             xStart++;
28             yStart++;
29             n = n - 2;
30         }
31         return result;
32     }
33 }

 

posted @ 2016-04-25 19:37  YuriFLAG  阅读(114)  评论(0)    收藏  举报