백준 14916번

https://www.acmicpc.net/problem/14916

14916번: 거스름돈

 

#include <iostream>

using namespace std;

int main() {
	int money, result;
	cin >> money;


	bool success = false;

	int five = money / 5;
	while (!success) {
		float two = (money - five * 5) % 2;

		if (two == 0) {
			success = true;
			result = five + (money - five * 5) / 2;
		}
		else {
			five--;
		}
	}
	if (money == 1 || money == 3) {
		cout << "-1";
		return 0;
	}
	cout << result;
}

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