Here, We see Contains Duplicate II problem Solution. This Leetcode problem is done in many programming languages like C++, Java, JavaScript, Python, etc., with different approaches.

Contains Duplicate II LeetCode Solution
Problem Statement ->
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
Contains Duplicate II Leetcode Solution C++ ->
class Solution {
public:
bool containsNearbyDuplicate(vector<int>& nums, int k)
{
unordered_set<int> s;
if (k <= 0) return false;
if (k >= nums.size()) k = nums.size() - 1;
for (int i = 0; i < nums.size(); i++)
{
if (i > k) s.erase(nums[i - k - 1]);
if (s.find(nums[i]) != s.end()) return true;
s.insert(nums[i]);
}
return false;
}
};
Code language: C++ (cpp)
Contains Duplicate II Leetcode Solution Java ->
class Solution {
public boolean containsNearbyDuplicate(int[] nums, int k) {
Set<Integer> set = new HashSet<Integer>();
for(int i = 0; i < nums.length; i++){
if(i > k) set.remove(nums[i-k-1]);
if(!set.add(nums[i])) return true;
}
return false;
}
}
Code language: Java (java)
Contains Duplicate II Leetcode Solution JavaScript ->
var containsNearbyDuplicate = function(nums, k) {
const hasmap = new Map();
for (let idx = 0; idx < nums.length; idx++) {
if (idx - hasmap.get(nums[idx]) <= k) {
return true;
}
hasmap.set(nums[idx], idx);
}
return false;
};
Code language: JavaScript (javascript)
Contains Duplicate II Leetcode Solution Python ->
class Solution:
def containsNearbyDuplicate(self, nums, k):
dic = {}
for i, v in enumerate(nums):
if v in dic and i - dic[v] <= k:
return True
dic[v] = i
return False
Code language: Python (python)