Submission #1202486

#	Time	Username	Problem	Language	Result	Execution time	Memory
1202486		Aiperiii	Stranded Far From Home (BOI22_island)	C++20	20 / 100	1029 ms	589824 KiB

island

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define all(x) x.begin(),x.end()
#define ff first
#define ss second
#define pb push_back
const int N=2e5+5;
vector <int> g[N];
int sum[N],a[N],ok[N];
void s(int v,int p){
    sum[v]=a[v];
    for(auto to : g[v]){
        if(to!=p){
            s(to,v);
        }
    }
    sum[p]+=sum[v];
}
void dfs(int v,int p){
    for(auto to : g[v]){
        if(to!=p){
            if(sum[to]>=a[v]){
                ok[to]=1;
                dfs(to,v);
            }
        }
    }
}
signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    int n,m;
    cin>>n>>m;
    
    for(int i=1;i<=n;i++){
        cin>>a[i];
    }
    while(m--){
        int u,v;
        cin>>u>>v;
        g[u].pb(v);
        g[v].pb(u);
    }
    if(n<=2000 && m<=2000){
        for(int i=1;i<=n;i++){
            set <pair <int,int> > st;
            int sum=0;
            st.insert({0,i});
            
            vector <int> vis(n+1);
            while(!st.empty()){
                
                int v=st.begin()->ss;
                int x=a[v];
                //cout<<v<<" "<<x<<"\n";
                st.erase(st.begin());
                if(x<=sum or (v==i && !vis[v])){
                    sum+=x;
                    vis[v]=1;
                    for(auto to : g[v]){
                        if(!vis[to]){
                            st.insert({a[to],to});
                        }
                    }
                }
                else{
                    break;
                }
                
            }
            bool ok=1;
            for(int j=1;j<=n;j++){
                if(!vis[j]){
                    
                    ok=0;break;
                }
            }
            if(ok)cout<<1;
            else cout<<0;
        }
        cout<<"\n";
        return 0;
    }
    s(1,0);
    ok[1]=1;
    dfs(1,0);
    for(int i=1;i<=n;i++)cout<<ok[i];
    cout<<"\n";
}
/*
 4 4
 2 2 4 3
 1 2
 1 3
 2 3
 3 4
 
 4 3
 4 2 2 1
 1 2
 3 2
 4 1
 
 10 9
 10 9 8 7 4 4 3 2 1 1
 1 2
 1 3
 2 4
 3 5
 5 7
 5 8
 7 9
 8 10
 3 6
 
 1110101000
*/

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