[백준][Java] 2961번 도영이가 만든 맛있는 음식 (브루트포스)

비트마스크래서 풀었는데 그냥 브루트포스

비트마스크로 도대체 어떻게 푸는 건지 모르겠음

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.ArrayList;
import java.util.List;
 
 
public class Main {
    
    private static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    private static BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
 
    private static int[][] raw;
    private static int res;
    private static int N;
    private static List<Integer> list;
    
    private static void cookComb(int currIdx, int pos, int num) {
        if(pos==num) {
            int sour = 1;
            int bitter = 0;
            
            for (Integer i : list) {
                sour *= raw[i][0];
                bitter += raw[i][1];
            }
            
            int diff = Math.abs(sour-bitter);
            if(diff<res)
                res = diff;
                
        }
        
        for(int i=currIdx+1; i<N; i++) {
            list.add(i);
            cookComb(i, pos+1, num);
            list.remove(list.size()-1);
        }
        
    }
    
    public static void main(String[] args) throws IOException{
        N = stoi(br.readLine());
        res = Integer.MAX_VALUE;
        raw = new int[N][2];
        list = new ArrayList<>();
        
        for(int i=0; i<N; i++) {
            String[] str = br.readLine().split(" ");
            raw[i][0] = stoi(str[0]);
            raw[i][1] = stoi(str[1]);
        }
        
        for(int num=1; num<=N; num++) {
            cookComb(-1, 0, num);
        }
        
        bw.write(String.valueOf(res));
        bw.flush();
        bw.close();
    }
    
 
    private static int stoi(String input) {
        return Integer.parseInt(input);
    }
}