Package g0801_0900.s0845_longest_mountain_in_array

Class Solution

  • All Implemented Interfaces:
    
public final class Solution

    845 - Longest Mountain in Array.

    Medium

    You may recall that an array arr is a mountain array if and only if:

    • arr.length >= 3

    • There exists some index i ( 0-indexed ) with 0 < i < arr.length - 1 such that:

    Given an integer array arr, return the length of the longest subarray, which is a mountain. Return 0 if there is no mountain subarray.

    Example 1:

    Input: arr = 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: arr = 2,2,2

    Output: 0

    Explanation: There is no mountain.

    Constraints:

    • <code>1 <= arr.length <= 10<sup>4</sup></code>

    • <code>0 <= arri<= 10<sup>4</sup></code>

    Follow up:

    • Can you solve it using only one pass?

    • Can you solve it in O(1) space?

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description

    • Field Summary

      Fields 
      Modifier and Type Field Description

    • Constructor Summary

      Constructors 
      Constructor Description
      Solution()

    • Enum Constant Summary

      Enum Constants 
      Enum Constant Description

    • Method Summary

      Modifier and Type Method Description
      final Integer longestMountain(IntArray arr)

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait