[LeetCode] Spiral Matrix II

 1 public class Solution {
 2     public int[][] generateMatrix(int n) {
 3         int num=1;
 4         int [][] result = new int[n][n];
 5         
 6         for (int i=0; i<n/2; i++) {
 7             for (int j=i; j<n-1-i; j++) {
 8                 result[i][j] = num++;
 9             }
10             for (int j=i; j<n-1-i; j++) {
11                 result[j][n-1-i] = num++;
12             }
13             for (int j=i; j<n-1-i; j++) {
14                 result[n-1-i][n-1-j] = num++;
15             }
16             for (int j=i; j<n-1-i; j++) {
17                 result[n-1-j][i] = num++;
18             }
19         }
20         
21         if (n%2==1) {
22             int line = n/2;
23             result[line][line] = num;
24         }
25         
26         return result;
27     }
28 }