Q219ContainsDuplicate.cpp

class Solution {
public:
    bool containsNearbyDuplicate(vector<int>& nums, int k) {
        unordered_map<int, int> myMap;
        
        for(int i=0; i<nums.size(); i++){
            if(myMap[nums[i]]!=0){
                if(abs(i+1-myMap[nums[i]])<=k)
                    return true;
                myMap[nums[i]]=i+1;
            }
            else
                myMap[nums[i]]=i+1;
        }
        return false;
    }
};