1380. Lucky Numbers in a Matrix

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.

1380. Lucky Numbers in a Matrix
``````struct Solution;

impl Solution {
fn lucky_numbers(matrix: Vec<Vec<i32>>) -> Vec<i32> {
let n = matrix.len();
let m = matrix[0].len();
let mut mins: Vec<i32> = vec![std::i32::MAX; n];
let mut maxs: Vec<i32> = vec![std::i32::MIN; m];
let mut res = vec![];
for i in 0..n {
for j in 0..m {
mins[i] = mins[i].min(matrix[i][j]);
maxs[j] = maxs[j].max(matrix[i][j]);
}
}
for i in 0..n {
for j in 0..m {
if mins[i] == matrix[i][j] && maxs[j] == matrix[i][j] {
res.push(matrix[i][j]);
}
}
}
res
}
}

#[test]
fn test() {
let matrix = vec_vec_i32![[3, 7, 8], [9, 11, 13], [15, 16, 17]];
let res = vec![15];
assert_eq!(Solution::lucky_numbers(matrix), res);
let matrix = vec_vec_i32![[1, 10, 4, 2], [9, 3, 8, 7], [15, 16, 17, 12]];
let res = vec![12];
assert_eq!(Solution::lucky_numbers(matrix), res);
let matrix = vec_vec_i32![[7, 8], [1, 2]];
let res = vec![7];
assert_eq!(Solution::lucky_numbers(matrix), res);
}
``````