Discussion on: Daily Challenge #215 - Difference of 2

vector<pair<int, int>> pairDifference(vector<int> arr){
    // store all the numbers in a set for ease of searching
    // cpp set stores all numbers in ascending order by default
    set<int> numbers(arr.begin(), arr.end());

    // stores the pairs which have difference of two
    vector<pair<int, int>> numPairs;

    for(int num : numbers){
        // for any number num if num+2 is also in the set
        // then include it in the vector
        if(numbers.find(num+2) != numbers.end()){
            numPairs.push_back(make_pair(num,num+2));
        }
    }
    return numPairs;
}