[leetCode] 1380. Lucky Numbers in a Matrix (Python)

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.

Solution

class Solution:
    def luckyNumbers (self, matrix: List[List[int]]) -> List[int]:
        matrix_len = len(matrix[0])
        row_len = len(matrix)
        for i in range(matrix_len):
            temp = []
            for j in range(row_len):
                temp.append(matrix[j][i])
                
            for k in range(row_len):
                if max(temp) == min(matrix[k]):
                    return [max(temp)]

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