cs-lab03/histogram.cpp

#include "histogram.h"
#include "histogram_internal.h"

void
find_minmax (const std::vector<double>& numbers, double& min, double& max) {
    if (numbers.size() == 0) {                                                    //empty array situation check
        return;
    } else {
        min = numbers[0];
        for (double element : numbers) {
            if (element < min) {
                min = element;
            }
        }

        max = numbers[0];
        for (double element : numbers) {
            if (element > max) {
                max = element;
            }
        }
        return;
    }
}


std::vector<std::size_t>
make_histogram (const std::vector<double>& numbers, std::size_t bin_count) {
    double max;
    double min;

    find_minmax(numbers, min, max);

    double bin_size = static_cast<double>(max - min) / (bin_count);

    std::vector <std::size_t> bins(bin_count);


    for (std::size_t i = 0; i < numbers.size(); ++i) {                                //Checking if a number is in a bin.
        bool found = false;
        for (std::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.
        }
    }
    return bins;
}