3488: Closest Equal Element Queries

Problem Statement

You are given a circular array nums and an array queries.

For each query i, you have to find the following:

  • The minimum distance between the element at index queries[i] and any other index j in the circular array, where nums[j] == nums[queries[i]]. If no such index exists, the answer for that query should be -1.

Return an array answer of the same size as queries, where answer[i] represents the result for query i.

Example 1:

Input: nums = [1,3,1,4,1,3,2], queries = [0,3,5]

Output: [2,-1,3]

Explanation:

  • Query 0: The element at queries[0] = 0 is nums[0] = 1. The nearest index with the same value is 2, and the distance between them is 2.
  • Query 1: The element at queries[1] = 3 is nums[3] = 4. No other index contains 4, so the result is -1.
  • Query 2: The element at queries[2] = 5 is nums[5] = 3. The nearest index with the same value is 1, and the distance between them is 3 (following the circular path: 5 -> 6 -> 0 -> 1).

Example 2:

Input: nums = [1,2,3,4], queries = [0,1,2,3]

Output: [-1,-1,-1,-1]

Explanation:

Each value in nums is unique, so no index shares the same value as the queried element. This results in -1 for all queries.

Constraints:

  • 1 <= queries.length <= nums.length <= 105
  • 1 <= nums[i] <= 106
  • 0 <= queries[i] < nums.length

Code Solution