백준 14889. 스타트와 링크 :: 돼지개발자

출저 : https://www.acmicpc.net/problem/14889

"비트마스크도 쓸수 있고, 그냥 DFS 로 짝지어서 할 수도 있고"

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.StringTokenizer;
 
class Main {
    
    static int N;
    static int[][] map;
    static boolean[] team;
    static int min = Integer.MAX_VALUE;
    
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        
        N = Integer.parseInt(br.readLine());
        
        map = new int[N][N];
        team = new boolean[N];
        
        for (int i = 0; i < N; i++) {
            StringTokenizer st = new StringTokenizer(br.readLine());
            for (int j = 0; j < N; j++) {
                map[i][j] = Integer.parseInt(st.nextToken());
            }
        }
        
        solve(0,0);
        System.out.println(min);
    }
    
    static void solve(int cnt, int cur) {
        
        if(cnt == N/2) {
            int sumA = 0;
            int sumB = 0;
            
            for (int i = 0; i < N; i++) {
                for (int j = i+1; j < N; j++) {
                    if(team[i] != team[j]) continue;
                    if(team[i]) {
                        sumA += map[i][j] + map[j][i];
                    }
                    else {
                        sumB += map[i][j] + map[j][i];
                    }
                }
            }
            min = Math.min(min, Math.abs(sumA-sumB));
            return;
        }
        
        for (int i = cur; i < N; i++) {
            team[i] = true;
            solve(cnt+1,i+1);
            team[i] = false;
        }
    }
    
}

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.StringTokenizer;
 
public class Main {
 
    static int N;
    static int[][] map;
    static boolean[] team;
    static int min = Integer.MAX_VALUE;
    
    public static void main(String[] args) throws IOException {    
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        
        N = Integer.parseInt(br.readLine());
        
        map = new int[N][N];
        team = new boolean[N];
        
        for (int i = 0; i < N; i++) {
            StringTokenizer st = new StringTokenizer(br.readLine());
            for (int j = 0; j < N; j++) {
                map[i][j] = Integer.parseInt(st.nextToken());
            }
        }
        
        for (int i = 0; i < (1 << N); i++) {
            for (int j = 0; j < N; j++) {
                if( (i & ( 1 << j)) != 0) {
                    team[j] = true;
                }
            }
            solve();
            Arrays.fill(team, false);
        }
        System.out.println(min);
    }
    
    static void solve() {
        int[] sum = new int[2];
        
        for (int i = 0; i < N; i++) {
            for (int j = 0; j < N; j++) {
                if(i == j || team[i] != team[j]) continue;
                
                if(team[i]) {
                    sum[0] += map[i][j];
                }
                else {
                    sum[1] += map[i][j];
                }
            }
        }
        min = Math.min(min, Math.abs(sum[0]-sum[1]));
    }
}