1 """
2 Given a matrix of m x n elements (m rows, n columns), return all elements of the matrix in spiral order.
3 Example 1:
4 Input:
5 [
6 [ 1, 2, 3 ],
7 [ 4, 5, 6 ],
8 [ 7, 8, 9 ]
9 ]
10 Output: [1,2,3,6,9,8,7,4,5]
11 Example 2:
12 Input:
13 [
14 [1, 2, 3, 4],
15 [5, 6, 7, 8],
16 [9,10,11,12]
17 ]
18 Output: [1,2,3,4,8,12,11,10,9,5,6,7]
19 """
20 class Solution:
21 def spiralOrder(self, matrix):
22 if not matrix:
23 return []
24 res = []
25 row_end = len(matrix)-1
26 col_end = len(matrix[0])-1
27 row_begin, col_begin = 0, 0
28 while row_begin <= row_end and col_begin <= col_end:#!!!关键
29 # 向右
30 j = col_begin
31 while j <= col_end:
32 res.append(matrix[row_begin][j])
33 j += 1
34 row_begin += 1
35 # 向下
36 i = row_begin
37 while i <= row_end:
38 res.append(matrix[i][col_end])
39 i += 1
40 col_end -= 1
41 if row_begin <= row_end:
42 # 向左
43 j = col_end
44 while j >= col_begin:
45 res.append(matrix[row_end][j])
46 j -= 1
47 row_end -= 1
48 if col_begin <= col_end:
49 # 向上
50 i = row_end
51 while i >= row_begin:
52 res.append(matrix[i][col_begin])
53 i -= 1
54 col_begin += 1
55 return res
