pLQB3m - Online C++ Compiler & Debugging Tool

#define all(v) v.begin() , v.end()
#define ll long long
#define LL LLONG_MAX
#include <algorithm>
#include <iostream>
#include <string>
#include <vector>
#define cin(a) for(auto &it : a) cin>>it
#define cout(a) for(auto &it : a) cout<<it<<" "
#define endl "\n"
#include <stack>
#include <queue>
#include <set>
#include <map>
#include <limits.h>
#include <cmath>
using namespace std;
const int N = 1e5+5;
 #define int ll
int dx[] = {1, 0, -1, 0};
int dy[] = {0, 1, 0, -1};
int oo = LL;
int n,m;
char arr[1005][1005];
bool vis[1005][1005];
void dfs(int i,int j){
    vis[i][j]=1;
    for (int k = 0; k < 4; k++)
    {
        if( arr[i+dx[k]][j+dy[k]]=='.'){
            if(vis[i+dx[k]][j+dy[k]]==0) dfs(i+dx[k],j+dy[k]);
        }
    }
}
void solve(){
 cin >>n>>m;
 for (int i = 0; i < n; i++)
 {
    for (int j = 0;j < m;j++)
 {
    cin >>arr[i][j];
 }
 }
 int cnt=0;
  for (int i = 0; i < n; i++)
 {
    for (int j = 0;j < m;j++)
 {
    if(arr[i][j]=='.' && vis[i][j]==0){
        dfs(i,j);
        cnt++;
    }
 }
 }
     cout << cnt<<endl;
}
 signed main()
{
    ios::sync_with_stdio(false),cin.tie(NULL),cout.tie(NULL);
 // written by _DeadKiller.
 int t=1;
//    cin >>t;
while (t--)
{
  solve();
}


}