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 }