English
219. Contains Duplicate II 
Problem Statement
Given an integer array nums and an integer k, return true if there are two distinct indicesi 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:
go
package main
func containsNearbyDuplicate(nums []int, k int) bool {
if len(nums) <= 1 {
return false
}
set := make(map[int]int)
// iterate over the array
for i, v := range nums {
// check if the value is in the set
if _, ok := set[v]; ok {
// if the value is in the set,
// check if the difference between the current index and the index of the value in the set
// is less than or equal to k
if i-set[v] <= k {
return true
}
}
// add the value to the set
set[v] = i
}
return false
}
...