2667 단지번호 붙이기

#include <stdio.h>
#include <queue>
 
using namespace std;
 
int house[30][30] = { 0 };
int val, n;
priority_queue<int> q;
 
void find(int i, int j);
 
int main() {
    scanf("%d", &n);
    getchar();
 
    for (int i = 1; i <= n; i++) {
        char tmp[30];
        for (int j = 1; j <= n; j++) {
            scanf("%c", &tmp[j]);
            house[i][j] = (int)tmp[j] - 48;
        }
        getchar();
    }
 
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= n; j++) {
            if (house[i][j] == 1) {
                val = 1;
                house[i][j] = 0;
 
                find(i, j);
                q.push(-val);
            }
        }
    }
 
    printf("%d\n", q.size());
 
    int size = q.size();
    for (int i = 1; i <= size; i++) {
        printf("%d\n", -q.top());
        q.pop();
    }
}
 
void find(int i, int j) {
    house[i][j] = 0;
    
    if (house[i - 1][j] == 1) {
        val++;
        house[i - 1][j] == 0;
        
        find(i - 1, j);
    }
    if (house[i][j-1] == 1) {
        val++;
        house[i][j - 1] == 0;
        
        find(i, j-1);
    }
    if (house[i+1][j] == 1) {
        val++;
        house[i + 1][j] == 0;
        
        find(i + 1, j);
    }
    if (house[i][j+1] == 1) {
        val++;
        house[i][j + 1] == 0;
        
        find(i, j+1);
    }
 
    return;
}