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.
Rust Solution
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);
}
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