2667 단지 번호 붙이기

BOJ::2667 단지 번호 붙이기

https://www.acmicpc.net/problem/2667

탐색 및 카운팅만 해주면 되는 문제.

라이브러리 안쓰고 풀고 싶은데 어렵기도 하고 습관이 쉽게 바뀌지 않는다..

<JAVA>

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Collections;
 
public class Main {
    
    static int n,cnt,ax,ay;
    static int map[][]=new int[25][25];
    static int dx[]={1,-1,0,0};
    static int dy[]={0,0,1,-1};
    
    public static void main(String args[]) throws IOException
    {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        ArrayList<Integer> res = new ArrayList();
        n = Integer.parseInt(br.readLine());
        
        for(int i = 0 ; i < n ; i++){
            String s=br.readLine();
            for(int j = 0 ; j < n ; j++){
                map[i][j]=s.charAt(j);
            }
        }
        
        for(int i = 0 ; i < n ; i ++){
            for(int j = 0 ; j < n ; j++){
                if(map[i][j]=='1'){
                    cnt=0;
                    int v = dfs(i,j);
                    res.add(v);
                }
            }
        }
        
        Collections.sort(res);
        System.out.println(res.size());
        for(int vv : res){
            System.out.println(vv+" ");
        }
    }
    public static int dfs(int x,int y){
        map[x][y]='0';
        cnt++;
        for(int i =0 ; i < 4 ; i++){
            ax=x+dx[i];
            ay=y+dy[i];
            if(ax>=0&&ay>=0&&ax<n&&ay<n){
                if(map[ax][ay]=='1')dfs(ax,ay);
            }
        }
        return cnt;
    }
}

<C++>

#include <iostream>
#include <string>
#include <algorithm>
using namespace std;
 
int res[25 * 25];
int n,cnt,ax,ay;
int map[25][25];
int dx[] = { 1,-1,0,0 };
int dy[] = { 0,0,1,-1 };
 
int dfs(int x, int y) {
    cnt++;
    map[x][y] = '0';
    for (int i = 0; i < 4; i++) {
        ax = x + dx[i];
        ay = y + dy[i];
        if (ax >= 0 && ay >= 0 && ax < n&&ay < n) {
            if (map[ax][ay] == '1') {
                dfs(ax, ay);
            }
        }
    }
    return cnt;
}
 
int main() {
    cin >> n;
    for (int i = 0; i < n; i++) {
        string s;
        cin >> s;
        for (int j = 0; j < n; j++) {
            map[i][j] = s.at(j);
        }
    }
 
    int idx = 0;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            if (map[i][j] == '1') {
                cnt = 0;
                int vv = dfs(i, j);
                res[idx] = vv;
                idx++;
            }
        }
    }
    
    sort(res, res + idx);
    cout << idx<< endl;
    for (int i = 0; i < idx; i++) {
        cout << res[i] << "\n";
    }
 
}