[C++] HackerRank 해커랭크 Connected Cells in a Grid

문제링크 : https://www.hackerrank.com/challenges/connected-cell-in-a-grid

#include <bits/stdc++.h>
using namespace std;
 
int mat[10][10];
int visited[10][10] = {0,};
int max_size = 0;
 
int find(int row, int col){
    if(!mat[row][col] || visited[row][col])
        return 0;
    visited[row][col] = 1;
    int size = 1;
    int x = row;
    int y = col;
    
    for(int i = -1; i <= 1; i++)
        for(int j = -1; j <= 1; j++){
            x = row + i;
            y = col + j;
            
            size += find(x, y);
        }
    return size;
}
 
int main() {
    int n, m;
    cin >> n;
    cin >> m;
    
    for(int i = 0; i < n; i++)
        for(int j = 0; j < m; j++)
            cin >> mat[i][j];
    
    for(int i = 0; i < n; i++)
        for(int j = 0; j < m; j++)
            if(mat[i][j] || !visited[i][j]){
                max_size = max(find(i,j), max_size);
            }
    cout << max_size;
    return 0;
}