# 0782. Transform to Chessboard

https://leetcode.com/problems/transform-to-chessboard

## Description

You are given an `n x n` binary grid `board`. In each move, you can swap any two rows with each other, or any two columns with each other.

Return _the minimum number of moves to transform the board into a **chessboard board**_. If the task is impossible, return `-1`.

A **chessboard board** is a board where no `0`'s and no `1`'s are 4-directionally adjacent.

**Example 1:**

![](https://assets.leetcode.com/uploads/2021/06/29/chessboard1-grid.jpg)

```
**Input:** board = [[0,1,1,0],[0,1,1,0],[1,0,0,1],[1,0,0,1]]
**Output:** 2
**Explanation:** One potential sequence of moves is shown.
The first move swaps the first and second column.
The second move swaps the second and third row.
```

**Example 2:**

![](https://assets.leetcode.com/uploads/2021/06/29/chessboard2-grid.jpg)

```
**Input:** board = [[0,1],[1,0]]
**Output:** 0
**Explanation:** Also note that the board with 0 in the top left corner, is also a valid chessboard.
```

**Example 3:**

![](https://assets.leetcode.com/uploads/2021/06/29/chessboard3-grid.jpg)

```
**Input:** board = [[1,0],[1,0]]
**Output:** -1
**Explanation:** No matter what sequence of moves you make, you cannot end with a valid chessboard.
```

**Constraints:**

* `n == board.length`
* `n == board[i].length`
* `2 <= n <= 30`
* `board[i][j]` is either `0` or `1`.

## ac

```java
```
