LeetCode 74. Search a 2D Matrix
Description:
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 from left to right.
- The first integer of each row is greater than the last integer of the previous row.
Example:
Consider the following matrix:
[
[1, 3, 5, 7],
[10, 11, 16, 20],
[23, 30, 34, 50]
]
Given target = 3, return true.
分析:
由于每一行每一列都有序,可以直接把二维数组转化为有序的一维数组,在有序数组中查找target即可。
下面代码查找target只是用了遍历,效率不够高,可以利用二分搜索算法来求解,效率会高一点。
代码如下:
1 | class Solution { |