1901. Find a Peak Element II

https://leetcode.com/problems/find-a-peak-element-ii

Description

A peak element in a 2D grid is an element that is strictly greater than all of its adjacent neighbors to the left, right, top, and bottom.

Given a 0-indexed m x n matrix mat where no two adjacent cells are equal, find any peak element mat[i][j] and return the length 2 array [i,j].

You may assume that the entire matrix is surrounded by an outer perimeter with the value -1 in each cell.

You must write an algorithm that runs in O(m log(n)) or O(n log(m)) time.

Example 1:

**Input:** mat = [[1,4],[3,2]]
**Output:** [0,1]
**Explanation:** Both 3 and 4 are peak elements so [1,0] and [0,1] are both acceptable answers.

Example 2:

**Input:** mat = [[10,20,15],[21,30,14],[7,16,32]]
**Output:** [1,1]
**Explanation:** Both 30 and 32 are peak elements so [1,1] and [2,2] are both acceptable answers.

Constraints:

• m == mat.length

• n == mat[i].length

• 1 <= m, n <= 500

• 1 <= mat[i][j] <= 105

• No two adjacent cells are equal.

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