java.lang.Object
g2401_2500.s2454_next_greater_element_iv.Solution

public class Solution extends java.lang.Object
2454 - Next Greater Element IV.

Hard

You are given a 0-indexed array of non-negative integers nums. For each integer in nums, you must find its respective second greater integer.

The second greater integer of nums[i] is nums[j] such that:

  • j > i
  • nums[j] > nums[i]
  • There exists exactly one index k such that nums[k] > nums[i] and i < k < j.

If there is no such nums[j], the second greater integer is considered to be -1.

  • For example, in the array [1, 2, 4, 3], the second greater integer of 1 is 4, 2 is 3, and that of 3 and 4 is -1.

Return an integer array answer, where answer[i] is the second greater integer of nums[i].

Example 1:

Input: nums = [2,4,0,9,6]

Output: [9,6,6,-1,-1]

Explanation:

0th index: 4 is the first integer greater than 2, and 9 is the second integer greater than 2, to the right of 2.

1st index: 9 is the first, and 6 is the second integer greater than 4, to the right of 4.

2nd index: 9 is the first, and 6 is the second integer greater than 0, to the right of 0.

3rd index: There is no integer greater than 9 to its right, so the second greater integer is considered to be -1.

4th index: There is no integer greater than 6 to its right, so the second greater integer is considered to be -1.

Thus, we return [9,6,6,-1,-1].

Example 2:

Input: nums = [3,3]

Output: [-1,-1]

Explanation: We return [-1,-1] since neither integer has any integer greater than it.

Constraints:

  • 1 <= nums.length <= 105
  • 0 <= nums[i] <= 109
  • Constructor Summary

    Constructors
    Constructor
    Description
     
  • Method Summary

    Modifier and Type
    Method
    Description
    int[]
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
  • Constructor Details

    • Solution

      public Solution()
  • Method Details

    • secondGreaterElement

      public int[] secondGreaterElement(int[] nums)