Package g2401_2500.s2454_next_greater_element_iv

Class Solution

  • public class Solution
extends 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 Detail

      • Solution

        public Solution()

    • Method Detail

      • secondGreaterElement

        public int[] secondGreaterElement​(int[] nums)