1 class Solution {
2 public int[] spiralOrder(int[][] matrix) {
3 if(matrix == null || matrix.length == 0){
4 return new int[]{};
5 }
6 int index = 0;
7 int l = 0, r = matrix[0].length-1, t = 0, b = matrix.length-1;
8 int[] ans = new int[(r+1) * (b+1)];
9 while(true){
10 for(int i = l; i <= r; i++) ans[index++] = matrix[l][i];
11 if(++t > b) break;
12 for(int i = t; i <= b; i++) ans[index++] = matrix[i][r];
13 if(--r < l) break;
14 for(int i = r; i >= l; i--) ans[index++] = matrix[b][i];
15 if(--b < t) break;
16 for(int i = b; i >= t; i--) ans[index++] = matrix[i][l];
17 if(++l > r) break;
18 }
19 return ans;
20 }
21 }
