Search⌘ K
AI Features

Solution: Next Greater Element IV

Explore the stack-based approach to solve the Next Greater Element IV problem efficiently. Learn to use two stacks to track elements waiting for their first and second greater elements, ensuring a linear time and space complexity solution. Understand how to implement this method, enabling you to handle similar coding interview challenges with confidence.

Statement

You are given a 0-indexed array of non-negative integers nums. For each element nums[i], determine its second greater element and return an array res where res[i] contains the second greater element of nums[i].

The second greater element of nums[i] is defined as the value nums[j] such that:

  • j > i

  • nums[j] > nums[i]

  • There exists exactly one index k where i < k < j and nums[k] > nums[i]

If no such index j exists, then the second greater element for nums[i] is -1.

Constraints:

  • ...