Next Greater Element II

arraystackmonotonic stack

Problem Statement

Given a circular integer array nums (i.e., the next element of nums[nums.length - 1] is nums[0] ), return the next greater number for every element in nums .

The next greater number of a number x is the first greater number to its traversing-order next in the array, which means you could search circularly to find its next greater number. If it doesn't exist, return -1 for this number.

Examples

Example 1

Input: nums = [1,2,1]
Output: [2,-1,2]
The first 1's next greater number is 2; 
The number 2 can't find next greater number. 
The second 1's next greater number needs to search circularly, which is also 2.

Example 2

Input: nums = [1,2,3,4,3]
Output: [2,3,4,-1,4]

Constraints

1 <= nums.length <= 10 ^4

-10 ^9 <= nums[i] <= 10 ^9

🤔

Medium

Difficulty

Topic Info

ModuleDSA

CategoryArray

Sub-topicStack