Submission #714682

#	Time	Username	Problem	Language	Result	Execution time	Memory
714682		ismayil	Stranded Far From Home (BOI22_island)	C++17	20 / 100	1084 ms	351392 KiB

island

#include <bits/stdc++.h>
#define int long long
//#define endl '\n'
using namespace std;
const int MAX = 2e5 + 5;
vector<int> adj[MAX];
int subtree[MAX], sum[MAX];
int s[MAX], ans[MAX], color[MAX];
void dfs_subtree(int u, int p){
    subtree[u] = s[u];
    for(auto v : adj[u]){
        if(v == p) continue;
        dfs_subtree(v, u);
        subtree[u] += subtree[v];
    }
}
void dfs(int u, int p){
    for(auto v : adj[u]){
        if(v == p) continue;
        if(subtree[v] < s[u]) continue;
        ans[v] = 1;
        dfs(v, u);
    }
}
bool bfs(int st){
    priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> q;
    q.push(make_pair(s[st], st));
    while (!q.empty())
    {
        int u = q.top().second;
        int w = q.top().first;
        q.pop();
        color[u] = 1;
        if(w > sum[st] && st != u) return false;
        sum[st] += w;
        for(auto v : adj[u]){
            if(!color[v]) q.push({s[v], v});
        }

    }
    return true;
}
signed main()
{
    ios::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    int n, m;
    cin>>n>>m;
    for(int i = 1; i <= n; i++) cin>>s[i];
    for (int i = 1; i <= m; i++)
    {
        int u, v;
        cin>>u>>v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    if(n <= 2000){
        for(int i = 1; i <= n; i++){
            memset(color, 0, sizeof(color));
            cout<<bfs(i);
        }
        cout<<endl;
        return 0;
    }
    dfs_subtree(1, 0);
    dfs(1, 0);
    ans[1] = 1;
    for(int i = 1; i <= n; i++){
        cout<<ans[i];
    }
    cout<<endl;
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 0 / 15
• Subtask 4: 0 / 30
• Subtask 5: 0 / 35