1 """ 2 Write an efficient algorithm that searches for a value in an m x n matrix. This matrix has the following properties: 3 Integers in each row are sorted in ascending from left to right. 4 Integers in each column are sorted in ascending from top to bottom. 5 Example: 6 Consider the following matrix: 7 [ 8 [1, 4, 7, 11, 15], 9 [2, 5, 8, 12, 19], 10 [3, 6, 9, 16, 22], 11 [10, 13, 14, 17, 24], 12 [18, 21, 23, 26, 30] 13 ] 14 Given target = 5, return true. 15 Given target = 20, return false. 16 """ 17 """ 18 剑指offer原题，很经典的一道题 19 AC 20 """ 21 class Solution: 22 def searchMatrix(self, matrix, target): 23 """ 24 :type matrix: List[List[int]] 25 :type target: int 26 :rtype: bool 27 """ 28 if not matrix: 29 return False 30 m = len(matrix) 31 n = len(matrix[0]) 32 i, j = m-1, 0 33 while i >= 0 and j < n: 34 if target > matrix[i][j]: 35 j += 1 36 elif target < matrix[i][j]: 37 i -= 1 38 else: 39 return True 40 return False