Submission #753917

#	Time	Username	Problem	Language	Result	Execution time	Memory
753917		Abito	Stranded Far From Home (BOI22_island)	C++14	20 / 100	1086 ms	243312 KiB

island

#include <bits/stdc++.h>
#define F first
#define S second
#define pb push_back
#define ppb pop_back
#define ep insert
#define endl '\n'
#define elif else if
#define pow pwr
#define sqrt sqrtt
#define int long long
typedef unsigned long long ull;
using namespace std;
const int N=2e5+5;
int n,m,a[N],dis[N],par[N],dp[N];
vector<int> adj[N],v;
bool cmp(int x,int y){
    return dis[x]<dis[y];
}
bool check(int source){
    priority_queue<pair<int,int>> pq;
    bool vis[n+5];
    memset(vis,0,sizeof(vis));
    int c=a[source];
    for (auto u:adj[source]) pq.push({-a[u],u});
    vis[source]=true;
    while (!pq.empty()){
        pair<int,int> x=pq.top();
        pq.pop();
        x.F*=-1;
        if (vis[x.S]) continue;
        if (x.F>c) break;
        vis[x.S]=true;
        c+=x.F;
        for (auto u:adj[x.S]) pq.push({-a[u],u});
    }
    bool ok=true;
    for (int i=1;i<=n;i++){
        if (vis[i]) continue;
        ok=false;
        break;
    }return ok;
}
void dfs(int node,int d,int p){
    dis[node]=d;
    dp[node]=a[node];
    par[node]=p;
    for (auto u:adj[node]){
        if (u==p) continue;
        dfs(u,d+1,node);
        dp[node]+=dp[u];
    }return;
}
int32_t main(){
    ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
    cin>>n>>m;
    for (int i=1;i<=n;i++) cin>>a[i];
    for (int i=1;i<=m;i++){
        int x,y;
        cin>>x>>y;
        adj[x].pb(y);
        adj[y].pb(x);
    }
    if (n<=2000 && m<=2000){
        for (int i=1;i<=n;i++) cout<<check(i);
        return 0;
    }
    dfs(1,0,0);
    for (int i=2;i<=n;i++) v.pb(i);
    sort(v.begin(),v.end(),cmp);
    //for (int i=1;i<=n;i++) cout<<dp[i]<<endl;
    for (auto node:v){
        if (dp[node]<a[par[node]]) continue;
        dp[node]=dp[par[node]];
    }
    for (int i=1;i<=n;i++) cout<<bool(dp[i]==dp[1]);
    return 0;
}

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