leetcode 240. Search a 2D Matrix II 模拟

Write an efficient algorithm that searches for a value in an m x n matrix. This matrix has the following properties:

Integers in each row are sorted in ascending from left to right.
Integers in each column are sorted in ascending from top to bottom.

For example,

Consider the following matrix:

[
[1,   4,  7, 11, 15],
[2,   5,  8, 12, 19],
[3,   6,  9, 16, 22],
[10, 13, 14, 17, 24],
[18, 21, 23, 26, 30]
]

Given target = 

5

, return 

true

.

Given target = 

20

, return 

false

.

class Solution(object):
def searchMatrix(self, matrix, target):
if len(matrix) == 0 or len(matrix[0]) == 0:
return False
n = len(matrix)
m = len(matrix[0])
i = 0
j = m-1
while i < n and j >= 0:
if matrix[i][j] == target:
return True
if matrix[i][j] > target:
j -= 1
else:
i += 1
return False

if __name__ == '__main__':
s = Solution()
print(s.searchMatrix([
[1, 4, 7, 11, 15],
[2, 5, 8, 12, 19],
[3, 6, 9, 16, 22],
[10, 13, 14, 17, 24],
[18, 21, 23, 26, 30]
] , 23))