Minimum Number of Flips to Convert Binary Matrix to Zero Matrix
Given an m x n binary matrix mat. In one step, you can choose one cell and flip it and all four neighbors of it if they exist. A flip changes 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.
Example 1
0 0 0 1
Input
mat = [[0,0],[0,1]]Output
3One possible solution is to flip (1, 0), then (0, 1), and finally (1, 1).
Example 2
0
Input
mat = [[0]]Output
0The given matrix is already a zero matrix, so no changes are needed.
Constraints
- m == mat.length
- n == mat[i].length
- 1 <= m, n <= 3
- mat[i][j] is either 0 or 1.