[백준 2231 자바] 분해합

문제

 

https://www.acmicpc.net/problem/2231

2231번: 분해합

접근

 

포인트

 

코드

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner in =new Scanner(System.in);
		int num = in.nextInt();
		
		ArrayList<Integer> list = new ArrayList<Integer>();
		
		//최소시작점 구하기
		int minStart = 0;
		int temp = num;
		
		while(temp>0) {
			minStart +=9;
			temp/=10;
		}
		minStart= num-minStart;
		
		//생성자 구하기
		for(int i=minStart; i < num;i++) {
			int bunhaehap = i; 
			int temp2 = i;
			
			while(temp2>0) {
				bunhaehap += temp2%10;
				temp2/=10;
			}
			
			if(bunhaehap == num) {
				list.add(i);
			}
		}
		
		//최솟값 출력
		if(list.size()==0) {
			System.out.println(0);
		}
		else {
			int min = list.get(0);
			for(int i=0; i<list.size();i++) {
				if(list.get(i)<min) {
					min = list.get(i);
				}
			}
			System.out.println(min);
		}
		
		
	}

}

 

 

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.ArrayList;
import java.util.Collections;
import java.util.StringTokenizer;

public class Main {
    public static void main(String[] args) throws  Exception{
        BufferedReader  br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter  bw = new BufferedWriter(new OutputStreamWriter(System.out));

        String line = br.readLine().trim();
        StringTokenizer st = new StringTokenizer(line);
        int N = Integer.parseInt(st.nextToken());

        findMaker(N);

        if(makers.size()==0){
            bw.write("0");
        }
        else{
            Collections.sort(makers);
            bw.write(String.valueOf(makers.get(0)));    
        }
        
        bw.flush();



    }
    public static ArrayList<Integer> makers = new ArrayList<Integer>();
    public static void findMaker(int N){
        for(int num =1 ;num<=N ;num++){
            int bunHaeHap = findBunHaeHap(num);
            //System.out.println("num:"+num+"bunHaHap:"+bunHaeHap);
            if(bunHaeHap==N){
                makers.add(num);
            }
        }
    }
    private static int findBunHaeHap(int num){
        int bunHaeHap = num;
        while(num>0){
            bunHaeHap+=num%10;
            num=num/10;
        }
        return bunHaeHap;
    }
}