cs-lab03/main.cpp

//main.cpp  -- the program gets number count, numbers and bin size, then builds a histogram.
//Task 15   -- make a scale under the histogram.

#include <iostream>
#include <vector>
#include <math.h>
using namespace std;

double find_ext(vector <double> array, short key)
{
    double ext = array[0];                                                  //Key "1" keeps the comparison the same.
    for(double element : array)                                             //Key "-1" reverses the comparison.
    {
        if(key * element > key * ext) {ext = element;}
    }
    return ext;
}

size_t find_ext(vector <size_t> array, short key)
{
    size_t ext = array[0];                                                  //Key "1" keeps the comparison the same.
    for(double element : array)                                             //Key "-1" reverses the comparison.
    {
        if(key * element > key * ext) {ext = element;}
    }
    return ext;
}



int main() {
    const size_t screen_width = 80;
    const size_t max_asterisk = screen_width - 3 - 1;


    size_t number_count;                                                    //Input variable.
    cerr << "Enter number count: ";
    cin >> number_count;
    vector<double> numbers(number_count);
    for (size_t i = 0; i < number_count; ++i) { cin >> numbers[i]; }
    size_t bin_count;
    cerr << "Enter bin count: ";
    cin >> bin_count;


    double max = find_ext(numbers, 1);                                      //Find min, max and bin size.
    double min = find_ext(numbers, -1);                                     //Key 1 stands for maximum, key -1 stands for minimum.
    double bin_size = static_cast<double>(max - min) / (bin_count);

    vector <size_t> bins(bin_count);


    for(size_t i = 0; i < number_count; ++i)                                //Checking if a number is in a bin.
    {
        bool found = false;
        for(size_t j = 0; (j < bin_count - 1) && !found; ++j)
        {
            if( (numbers[i] >= (min + j * bin_size)) &&                     //Where (min + j * bin_size) is equal to the lower border
            (numbers[i] < (min + (j + 1) * bin_size)) )                     //and (min + (j + 1) * bin_size) is equal to the higher border.
            {
                ++bins[j];
                found = true;
            }
        }
        if(!found) {++bins[bin_count - 1];}                                 //A special case when current number is equal to the maximum.
    }




    size_t max_bin = find_ext(bins, 1);                                     //Finds a bin with the maximum size. Key 1 stands for maximum.
    double modifier;

    /*
     * In case when maximum bin > 76, histogram will be scaled according to
     * the formula "max_asterisk * (static_cast<double>(bins[i]) / max_bin)"
     *          or "bins[i] * (static_cast<double>(max_asterisk) / max_bin)".
     * In other case, histogram won't be scaled, i.e, asterisk count depends on the current bin number.
     */

    if(max_bin > 76) {modifier = static_cast<double>(max_asterisk) / (max_bin);}
    else {modifier = 1;}

    for(long unsigned int i = 0; i < bin_count; ++i)                                      //Histogram output with alignment, if necessary.
    {
        if(bins[i] >= 10)
        {
            if(bins[i] >= 100) {cout << bins[i] << '|';}                    //Output a three-digit number.
            else {cout << ' ' << bins[i] << '|';}                           //Output a two-digit number with alignment.
        }
        else {cout << "  " << bins[i] << '|';}                              //Output a single-digit number with alignment.


        size_t height = modifier * bins[i];                                 //Height stands for the number of output asterisks.
        for(long unsigned int k = 0; k < height; ++k)
            cout << '*';
        cout << "\n";
    }



    //Task 15.


    size_t interval_task;
    cerr << "Enter interval size: ";
    cin >> interval_task;

    if((interval_task >= 4) && (interval_task <= 9))                        //The scale under the histogram.
    {
        size_t times;
        if(modifier == 1) {times = static_cast<size_t>(ceil(max_bin / interval_task) + 1);}
        else {times = static_cast<size_t>(ceil(max_asterisk / interval_task) + 1);}



        cout << "   |";                                                     //1st row output.
        for(long unsigned int i = 0; i < times; ++i)
        {
            for(long unsigned int k = 0; k < interval_task - 1; ++k)
                cout << '*';
            cout << '|';
        }
        cout << '\n';



        cout << "   " << 0;                                                 //2nd row output.
        for(long unsigned int i = 0; i < (interval_task - 1); ++i)                        //Distance from the first axis to the second.
            cout << ' ';
        cout << interval_task;

        //  (Number of intervals between the second and last * Interval size) - Last axis.

        if(times > 1)
        {
            for(long unsigned int i = 0; i < (times - 1) * (interval_task) - 1; ++i)
                cout << ' ';
            cout << times * interval_task;
        }
    }

    else {cout << "ERROR";}

    return 0;
}