Submission

[PPPPPPPPPPPPPPPPPPPPPPPPP]

Score: 100

User: Nagornz

Problemset: เกาะที่ใหญ่ที่สุด

Language: cpp

Time: 0.003 second

Submitted On: 2025-03-25 17:56:19

#include <bits/stdc++.h>
#define int long long
#define double long double
#define pii pair <int,int>
#define tiii tuple <int, int, int>
#define f first
#define s second
#define all(x) x.begin(), x.end()
#define ub(a, b) upper_bound(a.begin(), a.end(), b) - a.begin()
#define lb(a, b) lower_bound(a.begin(), a.end(), b) - a.begin()
#define ve vector
#define graph(a, n) vector <int> a[n];
#define wgraph(a, n) vector <pii> a[n];
#define emb emplace_back
#define em emplace
#define ins insert
#define er erase
#define iShowSpeed cin.tie(NULL)->sync_with_stdio(false)

using namespace std;

template <typename T>
using greater_priority_queue = priority_queue<T, vector<T>, greater<T>>;

const int mod = 1e9 + 7;
const int inf = 1e18;

int dx[4] = {1, 0, -1, 0};
int dy[4] = {0, 1, 0, -1};

int32_t main(){
    iShowSpeed;
    int n, m; cin >> n >> m;
    char a[n][m];
    for (int i = 0; i < n; i++) for (int j = 0; j < m; j++) cin >> a[i][j];
    int ans = 0;
    bool visited[n][m];
    memset(visited, false, sizeof visited);
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            if (!visited[i][j] && a[i][j] == '1') {
                visited[i][j] = true;
                queue <pii> q;
                q.emplace(i, j);
                int cnt = 1;
                while (!q.empty()) {
                    auto [x, y] = q.front(); q.pop();
                    for (int i = 0; i < 4; i++) {
                        int nx = x + dx[i], ny = y + dy[i];
                        if (nx < 0 || nx >= n || ny < 0 || ny >= m || visited[nx][ny] || a[nx][ny] == '0') continue;
                        q.emplace(nx, ny);
                        visited[nx][ny] = true;
                        cnt++;
                    }
                }
                ans = max(ans, cnt);
            }
        }
    }
    cout << ans;
}