题目
Given a non-empty 2D matrix matrix and an integer k, find the max sum of a rectangle in the matrix such that its sum is no larger than k.
Example:
Given matrix = [
[1, 0, 1],
[0, -2, 3]
]
k = 2
The answer is 2. Because the sum of rectangle [[0, 1], [-2, 3]] is 2 and 2 is the max number no larger than k (k = 2).
Note:
- he rectangle inside the matrix must have an area > 0.
- hat if the number of rows is much larger than the number of columns?
Credits:Special thanks to @fujiaozhu for adding this problem and creating all test cases.
解题思路
见程序注释