Package g0401_0500.s0496_next_greater_element_i

Class Solution

  • public class Solution
extends Object
    496 - Next Greater Element I.

    Easy

    The next greater element of some element x in an array is the first greater element that is to the right of x in the same array.

    You are given two distinct 0-indexed integer arrays nums1 and nums2, where nums1 is a subset of nums2.

    For each 0 <= i < nums1.length, find the index j such that nums1[i] == nums2[j] and determine the next greater element of nums2[j] in nums2. If there is no next greater element, then the answer for this query is -1.

    Return an array ans of length nums1.length such that ans[i] is the next greater element as described above.

    Example 1:

    Input: nums1 = [4,1,2], nums2 = [1,3,4,2]

    Output: [-1,3,-1]

    Explanation:

    The next greater element for each value of nums1 is as follows:

    • 4 is underlined in nums2 = [1,3,4,2]. There is no next greater element, so the answer is -1.

    • 1 is underlined in nums2 = [1,3,4,2]. The next greater element is 3.

    • 2 is underlined in nums2 = [1,3,4,2]. There is no next greater element, so the answer is -1.

    Example 2:

    Input: nums1 = [2,4], nums2 = [1,2,3,4]

    Output: [3,-1]

    Explanation:

    The next greater element for each value of nums1 is as follows:

    • 2 is underlined in nums2 = [1,2,3,4]. The next greater element is 3.

    • 4 is underlined in nums2 = [1,2,3,4]. There is no next greater element, so the answer is -1.

    Constraints:

    • 1 <= nums1.length <= nums2.length <= 1000
    • 0 <= nums1[i], nums2[i] <= 104
    • All integers in nums1 and nums2 are unique.
    • All the integers of nums1 also appear in nums2.

    Follow up: Could you find an O(nums1.length + nums2.length) solution?

    • Constructor Detail

      • Solution

        public Solution()

    • Method Detail

      • nextGreaterElement

        public int[] nextGreaterElement​(int[] nums1,
                                int[] nums2)