Minimum Number of Flips to Convert Binary Matrix to Zero Matrix

arrayhash tablebit manipulation

Problem Statement

Given a m x n binary matrix mat . In one step, you can choose one cell and flip it and all the four neighbors of it if they exist (Flip is changing 1 to 0 and 0 to 1 ). A pair of cells are called neighbors if they share one edge.

Return the minimum number of steps required to convert mat to a zero matrix or -1 if you cannot.

A binary matrix is a matrix with all cells equal to 0 or 1 only.

A zero matrix is a matrix with all cells equal to 0 .

Examples

Example 1

Input: mat = [[0,0],[0,1]]
Output: 3
One possible solution is to flip (1, 0) then (0, 1) and finally (1, 1) as shown.

Example 2

Input: mat = [[0]]
Output: 0
Given matrix is a zero matrix. We do not need to change it.

Example 3

Input: mat = [[1,0,0],[1,0,0]]
Output: -1
Given matrix cannot be a zero matrix.

Constraints

m == mat.length

n == mat[i].length

1 <= m, n <= 3

mat[i][j] is either 0 or 1 .

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Hard

Difficulty

Topic Info

ModuleDSA

CategoryArray

Sub-topicHash Table