leetcode74

 1 import bisect
 2 class Solution:
 3     def searchMatrix(self, matrix: 'List[List[int]]', target: int) -> bool:
 4         rows = len(matrix)
 5         if rows == 0:
 6             return False
 7         columns = len(matrix[0])
 8         if columns == 0:
 9             return False
10         rowlist = []
11         for i in range(rows):
12             rowlist.append(matrix[i][0])
13
14         rownum = bisect.bisect_left(rowlist, target)
15
16         if rownum >= rows:
17             rownum -= 1
18         elif rownum > 0:
19             if rowlist[rownum] == target:
20                 return True
21             else:
22                 rownum -= 1
23         collist = matrix[rownum]
24         idx = bisect.bisect_left(collist, target)
25         if idx >= columns:
26             return False
27         return collist[idx] == target

先按照列进行二分查找，找到符合的行，再对这一行进行二分查找。