Class Solution
Medium
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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Constructor Summary
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Method Summary
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
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Constructor Details
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Solution
public Solution()
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Method Details
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findPeakGrid
public int[] findPeakGrid(int[][] mat)
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