BEAKJOON JAVA ALGORITHM #2839(설탕배달)

https://www.acmicpc.net/problem/2839

import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; public class a2839 { public static void main(String[] args) throws NumberFormatException, IOException { BufferedReader br=new BufferedReader(new InputStreamReader(System.in)); int num=Integer.parseInt(br.readLine()); int[] a=new int[num+1]; a[0]=0; a[1]=-1; a[2]=-1; for(int i=3;i<=num;i++){ if(i<5 && a[i-3]!=-1){ a[i]=a[i-3]+1; }else if(i>=5 && a[i-5]!=-1){ a[i]=a[i-5]+1; }else if(i%3==0){ a[i]=i/3; }else if(i%5==0){ a[i]=i/5; }else{ a[i]=-1; } } System.out.println(a[num]); } }