[알고리즘] 백준 2839 설탕 배달 - JAVA

www.acmicpc.net/problem/2839

2839번: 설탕 배달

 

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

class Main {

    static int n;
    static int[] dp;
    static int[] arr = {3, 5};

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String s = br.readLine();
        n = Integer.parseInt(s);
        dp = new int[n + 1];

        int mod = n % 5;
        int div = n / 5;

        if (n == 4 || n == 7) {
            System.out.println(-1);
        }
        else if (mod == 0) {
            System.out.println(div);
        }
        else if (mod == 2 || mod == 4){
            System.out.println(div + 2);
        }
        else {
            System.out.println(div + 1);
        }

    }
}