- Difficulty: Easy
- Tags: LeetCode, Easy, Array, Two Pointers, leetcode-2200, O(n), O(1)
Problem
You are given a 0-indexed integer array nums
and two integers key
and k
. A k-distant index is an index i
of nums
for which there exists at least one index j
such that |i - j| <= k
and nums[j] == key
.
Return a list of all k-distant indices sorted in increasing order.
Example 1:
Input: nums = [3,4,9,1,3,9,5], key = 9, k = 1 Output: [1,2,3,4,5,6] Explanation: Here,nums[2] == key
andnums[5] == key. - For index 0, |0 - 2| > k and |0 - 5| > k, so there is no j
where|0 - j| <= k
andnums[j] == key. Thus, 0 is not a k-distant index. - For index 1, |1 - 2| <= k and nums[2] == key, so 1 is a k-distant index. - For index 2, |2 - 2| <= k and nums[2] == key, so 2 is a k-distant index. - For index 3, |3 - 2| <= k and nums[2] == key, so 3 is a k-distant index. - For index 4, |4 - 5| <= k and nums[5] == key, so 4 is a k-distant index. - For index 5, |5 - 5| <= k and nums[5] == key, so 5 is a k-distant index. - For index 6, |6 - 5| <= k and nums[5] == key, so 6 is a k-distant index.
Thus, we return [1,2,3,4,5,6] which is sorted in increasing order.
Example 2:
Input: nums = [2,2,2,2,2], key = 2, k = 2 Output: [0,1,2,3,4] Explanation: For all indices i in nums, there exists some index j such that |i - j| <= k and nums[j] == key, so every index is a k-distant index. Hence, we return [0,1,2,3,4].
Constraints:
1 <= nums.length <= 1000
1 <= nums[i] <= 1000
key
is an integer from the arraynums
.1 <= k <= nums.length