Submission #913812

#	Time	Username	Problem	Language	Result	Execution time	Memory
913812		abcvuitunggio	Closing Time (IOI23_closing)	C++17	83 / 100	518 ms	49144 KiB

closing

#include "closing.h"
#include <bits/stdc++.h>
using namespace std;
vector <pair <int, int>> ke[200001];
long long d[200001][2],cur;
int p[200001],ch[200001],vis[200001],inset[200001];
set <pair <long long, int>> s,s2;
void dfs(int u, int i, int par=-1){
    for (auto [v,w]:ke[u])
        if (v!=par){
            d[v][i]=d[u][i]+w;
            p[v]=u;
            dfs(v,i,u);
        }
}
void dfs2(int u, int par){
    for (auto [v,w]:ke[u]){
        if (!ch[v]&&v!=par){
            if (!vis[v]&&min(d[v][0],d[v][1])*2>max(d[v][0],d[v][1])){
                s2.insert({max(d[v][0],d[v][1]),v});
                inset[v]=1;
            }
            dfs2(v,u);
        }
    }
}
int max_score(int N, int X, int Y, long long K, vector<int> U, vector<int> V, vector<int> W){
    for (int i=0;i<N-1;i++){
        ke[U[i]].push_back({V[i],W[i]});
        ke[V[i]].push_back({U[i],W[i]});
    }
    memset(ch,0,sizeof(ch));
    memset(inset,0,sizeof(inset));
    memset(vis,0,sizeof(vis));
    d[X][0]=d[Y][1]=0;
    dfs(X,0);
    dfs(Y,1);
    for (;X!=Y;X=p[X])
        ch[X]=1;
    ch[Y]=1;
    int res=0,cnt=0;
    for (int i=0;i<N;i++)
        s.insert({min(d[i][0],d[i][1]),i});
    cur=0;
    while (!s.empty()&&cur+(*s.begin()).first<=K){
        cur+=(*s.begin()).first;
        res++;
        s.erase(s.begin());
    }
    s.clear();
    cur=0;
    for (int i=0;i<N;i++){
        if (ch[i]){
            s.insert({abs(d[i][0]-d[i][1]),i});
            cur+=min(d[i][0],d[i][1]);
            cnt++;
        }
        else{
            s.insert({min(d[i][0],d[i][1]),i});
            if (min(d[i][0],d[i][1])*2<=max(d[i][0],d[i][1]))
                s.insert({abs(d[i][0]-d[i][1]),i});
        }
    }
    while (!s.empty()){
        int x=0,i=0,y=0;
        auto [c,u]=*s.begin();
        s.erase(s.begin());
        if (s2.empty())
            x=c,i=u,y=1;
        else{
            auto [c2,u2]=*s2.begin();
            s2.erase(s2.begin());
            if (s.empty()){
                s.insert({c,u});
                x=c2;
                i=u2;
                y=2;
            }
            else{
                if (c+(*s.begin()).first<c2){
                    s2.insert({c2,u2});
                    x=c;
                    i=u;
                    y=1;
                }
                else{
                    s.insert({c,u});
                    x=c2;
                    i=u2;
                    y=2;
                }
            }
        }
        if (cur+x>K)
            break;
        cur+=x;
        cnt+=y;
        if (y==1&&!vis[i]){
            if (ch[i])
                dfs2(i,i);
            else{
                s.insert({abs(d[i][0]-d[i][1]),i});
                if (inset[i])
                    s2.erase(s2.find({max(d[i][0],d[i][1]),i}));
            }
        }
        if (y==2&&!vis[i])
            s.erase(s.find({min(d[i][0],d[i][1]),i}));
        vis[i]=1;
    }
    while (!s.empty()&&cur+(*s.begin()).first<=K){
        cur+=(*s.begin()).first;
        cnt++;
        s.erase(s.begin());
    }
    while (!s2.empty()&&cur+(*s2.begin()).first<=K){
        cur+=(*s2.begin()).first;
        cnt+=2;
        s2.erase(s2.begin());
    }
    s.clear();
    s2.clear();
    for (int i=0;i<N;i++)
        ke[i].clear();
    return max(res,(cur>K?0:cnt));
}

• Subtask 0: 0 / 0
• Subtask 1: 8 / 8
• Subtask 2: 9 / 9
• Subtask 3: 12 / 12
• Subtask 4: 14 / 14
• Subtask 5: 9 / 9
• Subtask 6: 11 / 11
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 0 / 17