Solution: Next Greater Element IV
Explore a stack-based solution to identify the second greater element for each item in a non-negative integer array. Learn to use two stacks to track elements waiting for their first and second greater values, enabling a linear time complexity approach for this common algorithmic problem.
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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 valuenums[j]such that:
j > i
nums[j] > nums[i]There exists exactly one index
kwherei < k < jandnums[k] > nums[i]If no such index
jexists, then the second greater element fornums[i]is-1.
Constraints:
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