BOJ4673 셀프넘버

https://www.acmicpc.net/problem/4673

4673번: 셀프 넘버

 

import java.util.*;
import java.io.*;
public class Main
{

    public static int nextNum(int num){
        String num_str = Integer.toString(num);
        int nextNum=num;
        for(int i=0; i<num_str.length();i++){
            nextNum+=(num_str.charAt(i)-'0');
        }
        return nextNum;
        
    }
	public static void main(String[] args) throws IOException {
	        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
	        boolean[] isNotSelfNum= new boolean[10_001];

	        for(int i=1; i<10_001;i++){
	            int num=i;
	            while(num<10001){
	                num = nextNum(num);
	                if (num>10000) break;
	                if (isNotSelfNum[num]) break;
	                isNotSelfNum[num]=true;
	            }
	        }
        
            for(int i=1; i<10_001;i++){
                if(!isNotSelfNum[i]) bw.write(i+"\n");
            }
            
            bw.flush();
	}
}