Problem Brief

Min Flips to Make Grid Palindrome

PHONE SCREEN

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You're working on a data storage system that represents information in a binary grid. For error correction and symmetry, every row and column must be a palindrome.

Additionally, due to hardware constraints, the total number of 1s must be divisible by 4.

You're allowed to flip any bits (0 -> 1). Return the minimum number of flips needed to make the grid valid.

1Example 1

Input

grid = [[1, 0, 1], [0, 1, 0], [1, 0, 0]]

Output

Explanation

Draft autosaves locally

public int minFlips(int[][] grid) {
  // write your code here
}

Input

grid

[[1, 0, 1], [0, 1, 0], [1, 0, 0]]

Output