Submission

Score: 100

User: patty

Problemset: เกาะที่ใหญ่ที่สุด

Language: cpp

Time: 0.003 second

Submitted On: 2026-02-25 16:10:48

#include <bits/stdc++.h>
using namespace std;
int main() {
	ios::sync_with_stdio(false);
	cin.tie(NULL);
	int m,n,maxsize=0,countsize=0;
	cin >> m >> n;
	vector<string> mp(m);
	queue<pair<int,int>> q;
	vector<vector<bool>> visited(m,vector<bool>(n,false));
	for(int i=0;i<m;i++) {
		cin >> mp[i];
	}
	int dx[] = {-1,0,1,0};
	int dy[] = {0,1,0,-1};
	for(int i=0;i<m;i++) {
		for(int j=0;j<n;j++) {
			if(mp[i][j]=='1') {
				q.push({i,j});
				visited[i][j]= true;
				countsize=1;
				while(!q.empty()) {
					int a =q.front().first;
					int b =q.front().second;
					//cout << a << " " << b << "\n";
					q.pop();
					for(int k=0;k<4;k++) {
						int anext = a+dx[k];
						int bnext = b+dy[k];
						if(anext<0 || bnext<0 || anext >m-1 || bnext>n-1) continue;
						if(visited[anext][bnext]==false && mp[anext][bnext]=='1') {
							q.push({anext,bnext});
							visited[anext][bnext] = true;
							countsize+=1;
						}
					}
				}
				maxsize = max(maxsize,countsize);
				
			}
		}
	}
	cout << maxsize;
}