LeetCode Top Interview 150
219. Contains Duplicate II
Easy
Given an integer array nums and an integer k, return true if there are two distinct indices i and j in the array such that nums[i] == nums[j] and abs(i - j) <= k.
Example 1:
Input: nums = [1,2,3,1], k = 3
Output: true
Example 2:
Input: nums = [1,0,1,1], k = 1
Output: true
Example 3:
Input: nums = [1,2,3,1,2,3], k = 2
Output: false
Constraints:
1 <= nums.length <= 105-109 <= nums[i] <= 1090 <= k <= 105
Solution
func containsNearbyDuplicate(nums []int, k int) bool {
duplicates := make(map[int]int, len(nums))
i := len(nums) - 1
for i >= 0 {
if idx, seen := duplicates[nums[i]]; seen {
if idx-i <= k {
return true
}
}
duplicates[nums[i]] = i
i--
}
return false
}