findMode.cpp

#include <iostream>
#include <iomanip>
#include <vector>
#include <algorithm>
using namespace std;

vector<int> modeVect(vector<int>& vect);

int main()
{
    vector<int> values;             //vector of ints generated by user input
    int num;                        //number added to vector
    char again;                     //continue entering values to the vector

    cout << "\nThis program will find the mode(s) of a list given by you." << endl;

    do
    {
        cout << "Please enter an integer to add to the list: ";

        while(!(cin >> num))
        {
            cin.clear();
            cin.ignore(256, '\n');
            cout << "ERROR\n";
            cout << "Please enter a valid integer to add to the list: ";
        }

        values.push_back(num);

        cout << "Would you like to add another integer to the list? (Y/N): ";
        cin >> again;

    }while (again == 'Y' || again == 'y');

    vector<int> mode(modeVect(values));

    cout << "\n\nThe mode(s) calculated: ";

    for(int i =0; i < mode.size(); i++)
    {
        cout << mode[i] << " ";
    }

    cout << "\n\n";

    return 0;
}

vector<int> modeVect (vector<int>& vect)
{
    sort(vect.begin(), vect.end());

    int current;                //current number being tallied
    int count = 0;              //iteration
    int old_freq = 0;           //compare to older mode
    vector<int> mode;

    do{
        int frequency = 0;      //frequency a number appears
        current = vect[count];

        for(int i = 0; i < vect.size(); i++)
        {
            if(vect[i] > current)
                break;

            if(vect[i] == current)
            {
                frequency++;
            }
        }

        if(frequency == old_freq)
        {
            for(int j = 0; j < mode.size(); j++)
            {
                if(mode[j] == current)
                    goto same;
            }
            mode.push_back(current);
        }

        if(frequency > old_freq)
        {
            mode.clear();
            mode.push_back(current);
            old_freq = frequency;
        }

        same:
        count++;

    }while (count < vect.size());

    return mode;

}