219. Contains Duplicate II | LeetCode Solution

 219. Contains Duplicate II | LeetCode Solution

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] <= 109
• 0 <= k <= 105

class Solution {

public:

    bool containsNearbyDuplicate(vector<int>& nums, int k) {

        unordered_map<int,int>mymap;

        if(k==0)return false;

        int st=0,n=nums.size();

        int end=0;

        while(end<=k && end<n){

            // cout<<end<<" ";

            auto it=mymap.find(nums[end]);

            if(it!=mymap.end())return true;

            else mymap[nums[end]]++;

            end++;

        }

        cout<<end;

        while(end<n){

            auto it=mymap.find(nums[st]);

            if(it!=mymap.end());

            mymap.erase(it);

            auto itt=mymap.find(nums[end]);

            if(itt!=mymap.end())return true;

            else mymap[nums[end]]++;

            st++;

            end++;

        }

        return false;

    }

};