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

bool
find_minmax(const vector<double>& numbers, double& min, double& max) {
	if (numbers.empty()) {
		return false;
	}

	min = numbers[0];
	max = numbers[0];
	for (double x : numbers) {
		if (x < min) {
			min = x;
		}
		else if (x > max) {
			max = x;
		}
	}

	return true;
}

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

	double min = 0, max = 0;
	find_minmax(numbers, min, max);

	double bin_size = (max - min) / bin_count;
	for (int i = 0; i < numbers.size(); i++) {
		bool found = false;
		for (int 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;
}