// Merge two sorted arrays
vector<int> merge(vector<int> vec1, vector<int> vec2){
    int len1 = vec1.size();
    int len2 = vec2.size();
    vector<int> vec;
    int i = 0, j=0;

    while(i < len1 || j < len2){
        if(i >= len1){
            vec.push_back(vec2[j]);
            j++;
        }
        else if(j >= len2){
            vec.push_back(vec1[i]);
            i++;
        }
        else{
            if(vec1[i] < vec2[j]){
                vec.push_back(vec1[i]);
                i++;
            }
            else if(vec1[i] == vec2[j]){
                vec.push_back(vec1[i]);
                vec.push_back(vec2[j]);
                i++; j++;
            }else{
                vec.push_back(vec2[j]);
                j++;
            }
        }
    }
    return vec;
}