Submission

Score: 100

User: Pxnny

Problemset: เกาะที่ใหญ่ที่สุด

Language: cpp

Time: 0.003 second

Submitted On: 2026-03-20 00:32:00

#include <bits/stdc++.h>
using namespace std;
#define pii pair<int, int>

string grid[200];
int ct=0, n, m;
bool vis[200][200];
int yy[] = {-1, 0, 0, 1};
int xx[] = {0, -1, 1, 0};
void floodfill(int i, int j){
    queue<pii> q;
    q.push({i, j});
    ct = 0;

    while(!q.empty()){
        int y = q.front().first;
        int x = q.front().second;
        q.pop();
        if(grid[y][x] == '0') continue;
        grid[y][x] = '0';
        ct++;
        for(i=0; i<4; i++){
            int ny = y + yy[i];
            int nx = x + xx[i];
            if(ny<0 || ny>=n || nx<0 || nx>=m) continue;
            if(grid[ny][nx] == '0') continue;
            q.push({ny, nx});
        }
    }

}
int main(){
    ios_base::sync_with_stdio(0), cin.tie(0);
    int ans=0;
    cin >> n >> m;
    for(int i=0; i<n; i++){
        cin >> grid[i];
    }
    //cout << "hello";
    for(int i=0; i<n; i++){
        for(int j=0; j<m; j++){
            ct = 0;
            if(grid[i][j] != '0'){
                //cout << i << " " << j << endl;
                floodfill(i, j);
                ans = max(ct, ans);
                //cout << ct << endl;
            }
        }
    }
    cout << ans;
}
/*
4 4
0011
0000
0111
1100

8 13
0010000100000
0000000111000
0110100000000
0100110010100
0100110011100
0000000000100
0000000111000
0000000110000

*/