cs-lab34/histogram.cpp

#include "histogram.h"
static 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<size_t> make_histogram(const std::vector<double>& numbers, size_t bin_count) {
	double min, max;
	find_minmax(numbers, min, max);
	std::vector<size_t> bins(bin_count);
	double bin_size = (max - min) / 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 low = min + j * bin_size;
			auto high = min + (j + 1) * bin_size;
			if ((low <= numbers[i]) && (numbers[i] < high))
			{
				bins[j]++;
				found = true;
			}
		}
		if (!found)
		{
			bins[bin_count - 1]++;
		}
	}
	return bins;
}