0845-longest-mountain-in-array.adoc

845. Longest Mountain in Array

{leetcode}/problems/longest-mountain-in-array/[LeetCode - Longest Mountain in Array^]

Let’s call any (contiguous) subarray B (of A) a mountain if the following properties hold:

• B.length >= 3

• There exists some 0 < i < B.length - 1 such that B[0] < B[1] < …​ B[i-1] < B[i] > B[i+1] > …​ > B[B.length - 1]

(Note that B could be any subarray of A, including the entire array A.)

Given an array A of integers, return the length of the longest mountain.

Return 0 if there is no mountain.

Example 1:

Input: [2,1,4,7,3,2,5]
Output: 5
Explanation: The largest mountain is [1,4,7,3,2] which has length 5.

Example 2:

Input: [2,2,2]
Output: 0
Explanation: There is no mountain.

Note:

• 0 ⇐ A.length ⇐ 10000

• 0 ⇐ A[i] ⇐ 10000

Follow up:

• Can you solve it using only one pass?

• Can you solve it in O(1) space?

link:{sourcedir}/_0845_LongestMountainInArray.java[role=include]