FastPrep

Description

Solutions

Regional Maximum Finder

📚RELATED PROBLEMS

You are given a 2D array. Your task is to find the regional maxima in the array and return a 2D array of size (X * 2) where each row contains the position [i, j] of a regional maximum.

Definition of Regional Maximum:

A cell (i, j) is considered a regional maximum if:

array[i][j] != 0

array[i][j] is the maximum value within its region.

Definition of Region:

For a cell (i, j) with value cell:

The region is defined as the rectangular area (i - cell to i + cell) * (j - cell to j + cell).

Exclude the corner cells from above: (i - cell, j - cell), (i - cell, j + cell), (i + cell, j - cell) and (i + cell, j + cell).

If the calculated region goes out of bounds, ignore those out-of-bound cells.

Function Description

Complete the function findRegionalMaxima in the editor.

findRegionalMaxima has the following parameter:

int[][] array: a 2D array of integers

Returns

int[][]: a 2D array where each row contains the position [i, j] of a regional maximum

Example 1:

Input:  array = [[3, 0, 1], [2, 0, 0], [0, 0, 0]]
Output: [[0, 0], [0, 2]] 
Explanation:
      
      The given 2D array is:
      
      [
        [3, 0, 1],
        [2, 0, 0],
        [0, 0, 0],
      ]
      
      

      
      The cell at position [0, 0] with value 3 is a regional maximum because:
      

        It is not 0.
        Its region is from [0, 0] to [3, 3] (excluding corners and out-of-bounds), and it is the maximum in this region.
      
      

      
      The cell at position [0, 2] with value 1 is a regional maximum because:
      

        It is not 0.
        Its region is from [0, 1] to [1, 3] (excluding corners and out-of-bounds), and it is the maximum in this region.
      
      

      
      Therefore, the output is [[0, 0], [0, 2]].

Constraints:

:)