Lord of the Rings

//C++17

#include <iostream>
#include <vector>

using namespace std;

// Function to simulate the proccess and
// find the lords of the ring
vector<int> find_lords_of_the_ring(int n, vector<int> potential)
{
    bool changes = true; // Changes flag
    while (changes)      // While there are still possible changes(removals) in the future
    {
        n = potential.size();      // Recalculate the size of the potential vector
        vector<int> rem(n, false); // Keep track if elements are removed in this round
        changes = false;           // Reset the changes flag

        for (int i = 0; i < n - 1; i++)
        {
            // If are in opposite directions
            if (potential[i] >= 0 && potential[i + 1] < 0)
            {
                if (abs(potential[i]) == abs(potential[i + 1])) // If the absolute values are equal, remove both
                {
                    rem[i] = true;
                    rem[i + 1] = true;
                }
                else if (abs(potential[i]) > abs(potential[i + 1])) // If the absolute value of the first is greater, remove the second
                    rem[i + 1] = true;
                else // If the absolute value of the second is greater, remove the first
                    rem[i] = true;

                changes = true; // There was a change
            }
        }

        if (!changes) // If there are no changes,
            break;

        // Set the new potential vector for the next round
        vector<int> new_potential;
        for (int i = 0; i < n; i++)
            if (!rem[i])
                new_potential.push_back(potential[i]);

        // Update the potential vector
        potential = new_potential;
    }

    return potential;
}

int main()
{
    // Read input
    int n;
    cin >> n;

    vector<int> potential(n);
    for (int &p : potential)
        cin >> p;

    // Find the answer and print it
    for (int p : find_lords_of_the_ring(n, potential))
        cout << p << " ";
    cout << endl;

    return 0;
}