C++(씨쁠쁠)(cplusplus)-백준(baekjoon)(BaekJoon)코딩 2667번:단지번호붙이기(BFS) 답

BFS로 푼 답 입니다

#include <iostream>
#include <queue>
#include <stdlib.h>
using namespace std;
 
int c[1000], a[26][26], d[26][26], N, cnt, dx[4] = { 0,0,1,-1 }, dy[4] = { 1,-1,0,0 };
int compare(const void *a, const void *b)
{
    return *(int*)a - *(int*)b;
}
void BFS(int i,int j, int cnt)
{
    queue <pair<int, int > > q;
    q.push(make_pair(i,j));
    d[i][j] = cnt;
    while (!q.empty())
    {
        i = q.front().first;
        j = q.front().second;
        q.pop();
        for(int k = 0; k< 4; k++)//4방향에서 살펴봐야 한다.
        {
            int nx = i + dx[k];
            int ny = j + dy[k];
            if (0 <= nx && nx < N && 0 <= ny && ny < N)
            {
                if (d[nx][ny] == 0 && a[nx][ny] == 1)
                {
                    q.push(make_pair(nx, ny)); 
                    d[nx][ny] = cnt;
                }
            }
 
        }
    }
}
int main() {
    cin >> N;
    for (int i = 0; i < N; i++)
        for (int j = 0; j < N; j++)
        {
            scanf("%1d", &a[i][j]);
        }
    for (int i = 0; i < N; i++)
    {
        for (int j = 0; j < N; j++)
        {
            if (!d[i][j] && a[i][j])
            {
                BFS(i, j, ++cnt);
            }
        }
    }
    for(int i = 0; i< N; i++)
        for (int j = 0; j < N; j++)
        {
            if (d[i][j])
            {
                c[d[i][j]]++;
            }
        }
    qsort(c, 1000, sizeof(int), compare);
    cout << cnt << '\n';
    for (int i = 0; i < 1000; i++)
    {
        
        if (c[i] !=0)
        {
            cout  << c[i] << '\n';
            
        }
    }
}