R8YekX - Online C++0x Compiler & Debugging Tool

#include <bits/stdc++.h>
#include <iostream>
using namespace std;


bool fnc(vector<int> arr,int k){
    unordered_map<int,int> mp;
    for(int i=0;i<arr.size();i++){
        if(mp.find(arr[i]) != mp.end() && i-mp[arr[i]]<=k){
            return true;
        }

        mp[arr[i]]=i;
    }

    return false;


}

int main(){
    vector<int> arr={1, 2, 2, 1, 2, 3};
    int k=2;
    if (fnc(arr, k)) {
        cout << "There are two equal numbers within distance " << k << std::endl;
    } else {
        cout << "No two equal numbers found within distance " << k << std::endl;
    }
    return 0;

}