[LintCode] Submatrix Sum 子矩阵之和

Posted 2020-08-04 Grandyang

 

Given an integer matrix, find a submatrix where the sum of numbers is zero. Your code should return the coordinate of the left-up and right-down number.

Have you met this question in a real interview? 

Yes

Example

Given matrix

[
  [1 ,5 ,7],
  [3 ,7 ,-8],
  [4 ,-8 ,9],
]

return [(1,1), (2,2)]

Challenge 

O(n3) time.