# 1284. Minimum Number of Flips to Convert Binary Matrix to Zero Matrix

https://leetcode.com/problems/minimum-number-of-flips-to-convert-binary-matrix-to-zero-matrix

## Description

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`.

**Example 1:**

![](https://assets.leetcode.com/uploads/2019/11/28/matrix.png)

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

**Example 2:**

```
**Input:** mat = [[0]]
**Output:** 0
**Explanation:** Given matrix is a zero matrix. We don't need to change it.
```

**Example 3:**

```
**Input:** mat = [[1,1,1],[1,0,1],[0,0,0]]
**Output:** 6
```

**Example 4:**

```
**Input:** mat = [[1,0,0],[1,0,0]]
**Output:** -1
**Explanation:** Given matrix can't be a zero matrix
```

**Constraints:**

* `m == mat.length`
* `n == mat[i].length`
* `1 <= m, n <= 3`
* `mat[i][j]` is either `0` or `1`.

## ac

```java
```
