cs-lab34/histogram.cpp

#include "histogram.h"
#include <vector>

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

std::vector<std::size_t> make_histogram(const std::vector<double> &numbers, size_t bin_count)
{
    double min = numbers[0];
    double max = numbers[0];
    find_minmax(numbers, min, max);
    double bin_size = ( max - min ) / bin_count;

    std::vector<std::size_t> bins ( bin_count );
    for (size_t i=0; i <  numbers.size(); i++ )
    {
        bool found = false;
        for (size_t j = 0; ( j < bin_count - 1 ) && !found; j++ )
        {
            auto lo = min + j * bin_size;
            auto hi = min + ( j + 1 ) * bin_size;
            if (lo <= numbers[i] && ( numbers[i] < hi ))
            {
                bins[j]++;
                found = true;
            }
        }
        if ( !found )
        {
            bins[bin_count-1]++;
        }
    }
    return bins;
}