231010 이모티콘 할인행사

private static class Emoticon {
	private double price;
	private double discount;

	public Emoticon(double price, double discount) {
		this.price = price;
		this.discount = discount;
	}

	public double getPrice() {
		return price;
	}

	public double getDiscount() {
		return discount;
	}
}

private int maxJoin = Integer.MIN_VALUE;
private int maxPrice = Integer.MIN_VALUE;

public int[] solution(int[][] users, int[] emoticons) {
	List<Emoticon> emoticonList = new ArrayList<>();
	double[] discounts = { 0.1, 0.2, 0.3, 0.4 };

	generateEmoticons(0, users, emoticonList, emoticons, discounts);

	return new int[] { maxJoin, maxPrice };
}

private void generateEmoticons(int depth, int[][] users, List<Emoticon> emoticons, int[] emoticonPrices,
		double[] discounts) {
	if (depth == emoticonPrices.length) {
		int totalJoinedUsers = 0;
		int totalSales = 0;

		for (int[] user : users) {
			int userDiscount = user[0];
			int userPrice = user[1];
			int userSum = calculateUserSum(emoticons, userDiscount);

			if (userSum >= userPrice) {
				totalJoinedUsers++;
			} else {
				totalSales += userSum;
			}
		}

		if (totalJoinedUsers > maxJoin) {
			maxJoin = totalJoinedUsers;
			maxPrice = totalSales;
		} else if (totalJoinedUsers == maxJoin && totalSales > maxPrice) {
			maxPrice = totalSales;
		}

		return;
	}

	for (double discount : discounts) {
		Emoticon emoticon = new Emoticon((1 - discount) * emoticonPrices[depth], discount * 100);
		emoticons.add(emoticon);
		generateEmoticons(depth + 1, users, emoticons, emoticonPrices, discounts);
		emoticons.remove(emoticon);
	}
}

private int calculateUserSum(List<Emoticon> emoticons, int userDiscount) {
	int sum = 0;
	for (Emoticon emoticon : emoticons) {
		double emoticonPrice = emoticon.getPrice();
		double emoticonDiscount = emoticon.getDiscount();

		if (emoticonDiscount >= userDiscount) {
			sum += emoticonPrice;
		}
	}
	return sum;
}

출처:https://school.programmers.co.kr/learn/courses/30/lessons/150368