Increasing Triplet Subsequence

arraygreedy

Problem Statement

Given an integer array nums , return true if there exists a triple of indices (i, j, k) such that i < j < k and nums[i] < nums[j] < nums[k] . If no such indices exists, return false .

Examples

Example 1

Input: nums = [1,2,3,4,5]
Output: true
Any triplet where i < j < k is valid.

Example 2

Input: nums = [5,4,3,2,1]
Output: false
No triplet exists.

Example 3

Input: nums = [2,1,5,0,4,6]
Output: true
One of the valid triplet is (1, 4, 5), because nums[1] == 1 < nums[4] == 4 < nums[5] == 6.

Constraints

1 <= nums.length <= 5 * 10 ^5

-2 ^31 <= nums[i] <= 2 ^31 - 1

Follow up: Could you implement a solution that runs in O(n) time complexity and O(1) space complexity?

🤔

Medium

Difficulty

Topic Info

ModuleDSA

CategoryArray

Sub-topicGreedy