# 1380. Lucky Numbers in a Matrix

<https://leetcode.com/problems/lucky-numbers-in-a-matrix>

## Description

Given a `m * n` matrix of **distinct** numbers, return all lucky numbers in the matrix in **any** order.

A lucky number is an element of the matrix such that it is the minimum element in its row and maximum in its column.

**Example 1:**

```
**Input:** matrix = [[3,7,8],[9,11,13],[15,16,17]]
**Output:** [15]
**Explanation:** 15 is the only lucky number since it is the minimum in its row and the maximum in its column
```

**Example 2:**

```
**Input:** matrix = [[1,10,4,2],[9,3,8,7],[15,16,17,12]]
**Output:** [12]
**Explanation:** 12 is the only lucky number since it is the minimum in its row and the maximum in its column.
```

**Example 3:**

```
**Input:** matrix = [[7,8],[1,2]]
**Output:** [7]
```

**Constraints:**

* `m == mat.length`
* `n == mat[i].length`
* `1 <= n, m <= 50`
* `1 <= matrix[i][j] <= 10^5`.
* All elements in the matrix are distinct.

## ac

```java
```