[BOJ] 1012번 유기농배추

들어가는 시점만 알면 된다.

#include <iostream>
#include <queue>
using namespace std;
int arr[51][51] {0};
int t,m,n,k;
int cnt;
void search(int x,int y)
{
    if(arr[y][x]){
        arr[y][x] = 0;
        if(x > 0)
            search(x-1,y);
        if(x < m)
            search(x+1,y);
        if(y > 0)
            search(x,y-1);
        if(y < n - 1)
            search(x,y+1);
    }
}
int main()
{
    cin >> t; 
    for(int a = 0; a < t; a++){
        cin >> m >> n >> k;
 
        for(int i = 0; i < k; i++)
        {
            int x,y;
            cin >> x >> y;
            arr[y][x] = 1;
        }
 
        for(int i =0; i < n; i++) {
            for(int j = 0; j < m; j++) {
                if(arr[i][j]) {
                    cnt++;
                    search(j,i);
                }
            }
        }
 
        cout << cnt << endl;    
        cnt = 0;
    }
    return 0;
}