알고리즘69 :: BOJ_13866_팀나누기

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.StringTokenizer;
 
public class 팀나누기 {
 
    static int[] arr;
    static ArrayList<Integer> al = new ArrayList<>();
    static ArrayList<Integer> al2 = new ArrayList<>();
    static int ans = Integer.MAX_VALUE;
    static void dfs(int nn) {
        if(nn==4) {
            if(al.size()==2 && al2.size()==2) {
                
                
                int team1 = 0;
                for(int i=0; i<al.size(); i++) {
                    team1 += al.get(i);
                }
                int team2 = 0;
                for(int j=0; j<al2.size(); j++) {
                    team2 += al2.get(j);
                }
                
                if(ans>Math.abs(team1-team2))
                    ans = Math.abs(team1-team2);
            }
        }else {
            al.add(arr[nn]);
            dfs(nn+1);
            al.remove(al.size()-1);
            
            al2.add(arr[nn]);
            dfs(nn+1);
            al2.remove(al2.size()-1);
        }
    }
    public static void main(String[] args)throws Exception {
        // TODO Auto-generated method stub
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st = new StringTokenizer(br.readLine());
        arr = new int[4];
        for(int i=0; i<arr.length; i++)
        {
            arr[i] = Integer.parseInt(st.nextToken());
        }
        dfs(0);
        System.out.println(ans);
    }
 
}
 

N = 4 제약 조건에서 

정확히 두개씩 인자를 가지고 최솟값을 확인하면된다.