Skip to content

Files

Latest commit

 

History

History

lucky-numbers-in-a-matrix

Folders and files

NameName
Last commit message
Last commit date

parent directory

..
 
 

< Previous                  Next >

Given an m x 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]
Explanation: 7 is the only lucky number since it is the minimum in its row and the maximum in its column.

Example 4:

Input: matrix = [[3,6],[7,1],[5,2],[4,8]]
Output: []
Explanation: There is no lucky number.

 

Constraints:

  • m == mat.length
  • n == mat[i].length
  • 1 <= n, m <= 50
  • 1 <= matrix[i][j] <= 105.
  • All elements in the matrix are distinct.

Related Topics

[Array] [Matrix]

Hints

Hint 1 Find out and save the minimum of each row and maximum of each column in two lists.
Hint 2 Then scan through the whole matrix to identify the elements that satisfy the criteria.