Submission

Score: 100

User: Fifaxmb

Problemset: เกาะที่ใหญ่ที่สุด

Language: cpp

Time: 0.004 second

Submitted On: 2026-08-11 20:45:32

#include<bits/stdc++.h>
using namespace std;
int dx[] = {0,0,-1,1};
int dy[] = {-1,1,0,0};
int main(){
    ios::sync_with_stdio(0);cin.tie(0);
    int n,m;cin >> n >> m;
    vector<string> v(n);
    vector<vector<bool>> vis(n,vector<bool>(m,0));
    for(int i =0;i < n;i++) cin >> v[i];
    int mx =0;
    for(int i = 0;i < n;i++){
        for(int j =0;j < m;j++){
            if(v[i][j] == '1' && !vis[i][j]){
                int cnt = 1;
                queue<pair<int,int>> q;
                q.push({i,j});
                vis[i][j] = 1;
                while(!q.empty()){
                    auto[x,y] = q.front();q.pop();
                    for(int d =0;d < 4;d++){
                        int xx = x + dx[d];
                        int yy = y + dy[d];
                        if(xx < 0 || yy < 0 || xx >= n || yy >= m || vis[xx][yy] || v[xx][yy] == '0') continue;
                        cnt ++;
                        q.push({xx,yy});
                        vis[xx][yy] = 1;
                    }
                }
                mx = max(cnt,mx);
            }
        }
    }
    cout << mx;
}