54. 螺旋矩阵
给你一个 m 行 n 列的矩阵 matrix ，请按照 顺时针螺旋顺序 ，返回矩阵中的所有元素。
示例 1：
输入：matrix = [[1,2,3],[4,5,6],[7,8,9]] 输出：[1,2,3,6,9,8,7,4,5]
示例 2：
输入：matrix = [[1,2,3,4],[5,6,7,8],[9,10,11,12]] 输出：[1,2,3,4,8,12,11,10,9,5,6,7]
提示：
m == matrix.lengthn == matrix[i].length1 <= m, n <= 10-100 <= matrix[i][j] <= 100相似题目
原站题解
python3 解法, 执行用时: 32 ms, 内存消耗: 15 MB, 提交时间: 2022-08-02 15:46:28
class Solution:
def spiralOrder(self, matrix: List[List[int]]) -> List[int]:
if not matrix or not matrix[0]:
return list()
rows, columns = len(matrix), len(matrix[0])
order = list()
left, right, top, bottom = 0, columns - 1, 0, rows - 1
while left <= right and top <= bottom:
for column in range(left, right + 1):
order.append(matrix[top][column])
for row in range(top + 1, bottom + 1):
order.append(matrix[row][right])
if left < right and top < bottom:
for column in range(right - 1, left, -1):
order.append(matrix[bottom][column])
for row in range(bottom, top, -1):
order.append(matrix[row][left])
left, right, top, bottom = left + 1, right - 1, top + 1, bottom - 1
return order
python3 解法, 执行用时: 44 ms, 内存消耗: 15 MB, 提交时间: 2022-08-02 15:46:14
class Solution:
def spiralOrder(self, matrix: List[List[int]]) -> List[int]:
if not matrix or not matrix[0]:
return list()
rows, columns = len(matrix), len(matrix[0])
visited = [[False] * columns for _ in range(rows)]
total = rows * columns
order = [0] * total
directions = [[0, 1], [1, 0], [0, -1], [-1, 0]]
row, column = 0, 0
directionIndex = 0
for i in range(total):
order[i] = matrix[row][column]
visited[row][column] = True
nextRow, nextColumn = row + directions[directionIndex][0], column + directions[directionIndex][1]
if not (0 <= nextRow < rows and 0 <= nextColumn < columns and not visited[nextRow][nextColumn]):
directionIndex = (directionIndex + 1) % 4
row += directions[directionIndex][0]
column += directions[directionIndex][1]
return order