[백준 2839] 설탕 배달 (C++/Python)

C++)

#include <iostream>

using namespace std;

int main(void) {
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);

	int n;
	cin >> n;

	int a = n/5;
	int b = -1;
	int temp = 0;
	
	while (a >= 0) {
		temp = n - a * 5;

		if ( temp % 3 == 0 ) {
			b = temp / 3;
			break;
		}
		else {
			a--;
			b = -1;
		}
	}

	if (b == -1)
		cout << -1;
	else
		cout << a + b;

	return 0;
}

 

 

Python)

import sys

n = int(sys.stdin.readline().rstrip())

a = n//5
b = -1
temp = 0

while a >= 0:
    temp = n - a * 5

    if temp%3 == 0:
        b = temp//3
        break
    else:
        a -= 1
        b = -1

print(-1 if b == -1 else a+b)