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>

using namespace std;

struct Input {
    vector<double> numbers;
    size_t bin_count{};
    //size_t interval_task{};
};


Input
input_data() {
    size_t number_count;
    cin >> number_count;

    Input in;

    in.numbers.resize(number_count);
    for (size_t i = 0; i < number_count; i++) {
        cin >> in.numbers[i];
    }

    cin >> in.bin_count;

    //cin >> in.interval_task;
    return in;
}

void
find_minmax(const std::vector<double>& numbers, double& min, double& max) {
    min = numbers[0];
    for(double element : numbers)
    {
        if(element < min) {min = element;}
    }

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


void
find_max(const std::vector<std::size_t>& numbers, std::size_t& max) {
    max = numbers[0];
    for(double element : numbers)
    {
        if(element > max) {max = element;}
    }
}

void
show_histogram_text(const std::vector<std::size_t>& bins){
    std::size_t max_bin;
    find_max(bins, max_bin);
    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>(74) / (max_bin);}
    else {modifier = 1;}

    for(std::size_t i = 0; i < bins.size(); ++i)                                      //Histogram output with alignment, if necessary.
    {
        if(bins[i] >= 10)
        {
            if(bins[i] >= 100) {std::cout << bins[i] << '|';}                    //Output a three-digit number.
            else {std::cout << ' ' << bins[i] << '|';}                           //Output a two-digit number with alignment.
        }
        else {std::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(size_t k = 0; k < height; ++k)
            std::cout << '*';
        std::cout << "\n";
    }
}

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;
}



int main() {
    auto in = input_data();
    auto bins = make_histogram(in.numbers, in.bin_count);
    show_histogram_text(bins);

    return 0;
}