Problem: 240. 搜索二维矩阵 II

思路 & 解题方法

暴力、二分、Z

复杂度

时间复杂度:

暴力： $O(mn)$
二分： $O(mlogn)$
Z: $O(m+n)$

空间复杂度:

添加空间复杂度, 示例： $O(n)$

暴力

class Solution:def searchMatrix(self, matrix: List[List[int]], target: int) -> bool:for x in matrix:for num in x:if num == target:return Truereturn False

二分

class Solution:def searchMatrix(self, matrix: List[List[int]], target: int) -> bool:for x in matrix:left, right = 0, len(matrix[0]) - 1while left <= right:mid = (left + right) // 2if x[mid] > target:right = mid - 1elif x[mid] < target:left = mid + 1else:return Truereturn False

bisect

class Solution:def searchMatrix(self, matrix: List[List[int]], target: int) -> bool:for x in matrix:idx = bisect.bisect_left(x, target)if idx < len(x) and x[idx] == target:return Truereturn False

Z

class Solution:def searchMatrix(self, matrix: List[List[int]], target: int) -> bool:m, n = len(matrix), len(matrix[0])x, y = 0, n - 1while x < m and y >= 0:if matrix[x][y] == target:return Trueif matrix[x][y] > target:y -= 1elif matrix[x][y] < target:x += 1return False