Contains Duplicate - 2.cpp

// 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.


class Solution {
public:
    bool containsNearbyDuplicate(vector<int>& nums, int k) {

        unordered_map<int, int> mp;
        int n = nums.size();

        for(int i=0;i<n;++i){
            if(mp.find(nums[i])!=mp.end()){
                if(abs(i-mp[nums[i]]) <=k){
                    return true;
                }
            }

            mp[nums[i]]=i;
        }
        
        return false;
    }
};