Distributes the given score over the given number of days.

students.cpp

#include <algorithm>
#include <iostream>
#include <random>

const int MIN_SCORE_PER_DAY = 5;
const int MAX_SCORE_PER_DAY = 10;

int main()
{
	std::random_device rd;
	std::mt19937 gen(rd());

	while (true)
	{
		int days, score;
		std::cout << "Enter the number of days, followed by the total score: ";
		std::cin >> days >> score;

		if ((days == 0) && (score == 0))
		{
			return 0;
		}
		else if ((days <= 0) || (score <= 0))
		{
			std::cout << "Error: days and score must be greater than 0!\n\n";
			continue;
		}

		// For .5 score distribution: first multiply the total by two,
		// then divide the results by two.
		score *= 2;

		for (; days; --days)
		{
			int max_score = days * (MAX_SCORE_PER_DAY * 2),
			    min_score = days * (MIN_SCORE_PER_DAY * 2);

			if (score > max_score)
			{
				std::cout << "Error: not enough days to distribute the score!";
				break;
			}
			else if (score < min_score)
			{
				std::cout << "Error: not enough score to distribute over the days!";
				break;
			}

			std::uniform_int_distribution<> distr(
				std::max(MIN_SCORE_PER_DAY * 2, score - max_score + MAX_SCORE_PER_DAY * 2),
				std::min(MAX_SCORE_PER_DAY * 2, score - min_score + MIN_SCORE_PER_DAY * 2));
			int result = distr(gen);

			score -= result;
			std::cout << (result / 2.0) << "  ";
		}

		std::cout << "\n\n";
	}
}