제출 #1012630

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1012630		JakobZorz	봉쇄 시간 (IOI23_closing)	C++17	43 / 100	86 ms	36812 KiB

closing

#include"closing.h"
#include<vector>
#include<iostream>
#include<queue>
#include<set>
#include<algorithm>
using namespace std;
typedef long long ll;

int n,x,y;
ll k;
vector<pair<int,int>>nodes[200000];
ll distx[200000];
ll disty[200000];

void dfs1(int node,int par,ll*dists){
    for(auto[ne,w]:nodes[node]){
        if(ne==par)
            continue;
        dists[ne]=dists[node]+w;
        dfs1(ne,node,dists);
    }
}

int lvl1(){
    vector<bool>vis(n);
    int res=0;
    ll kr=k;
    priority_queue<pair<ll,int>>q;
    q.push({0,x});
    q.push({0,y});
    vis[x]=true;
    vis[y]=true;
    while(q.size()){
        int node=q.top().second;
        ll cost=-q.top().first;
        q.pop();
        if(cost>kr)
            break;
        res++;
        kr-=cost;
        for(auto[ne,w]:nodes[node]){
            if(vis[ne])
                continue;
            vis[ne]=true;
            q.push({-min(distx[ne],disty[ne]),ne});
        }
    }
    return res;
}

int get(multiset<ll>&s,ll money){
    int res=0;
    for(ll i:s){
        if(i>money)
            break;
        res++;
        money-=i;
    }
    return res;
}

int solve(vector<pair<ll,ll>>opts,ll money){
    for(auto&[i,j]:opts)
        swap(i,j);
    sort(opts.begin(),opts.end());
    for(auto&[i,j]:opts)
        swap(i,j);
    
    multiset<ll>s;
    for(auto[i,j]:opts)
        s.insert(i);
    
    int res=get(s,money);
    int res2=0;
    for(auto[i,j]:opts){
        money-=i;
        s.erase(s.find(i));
        s.insert(j);
        res2++;
        if(money<0)
            break;
        res=max(res,res2+get(s,money));
    }
    return res;
}

int lvl2(){
    int cres=0;
    ll money=k;
    vector<pair<ll,ll>>opts;
    for(int i=0;i<n;i++){
        if(distx[i]+disty[i]==distx[y]){ // is on the path from x to y
            cres++;
            money-=min(distx[i],disty[i]);
            opts.emplace_back(max(distx[i],disty[i])-min(distx[i],disty[i]),1e18);
        }else{
            opts.emplace_back(min(distx[i],disty[i]),max(distx[i],disty[i])-min(distx[i],disty[i]));
        }
    }
    if(money<0)
        return 0;
    
    return cres+solve(opts,money);
}

int max_score(int N,int X,int Y,ll K,vector<int>U,vector<int>V,vector<int>W){
    n=N;
    x=X;
    y=Y;
    k=K;
    for(int i=0;i<n;i++){
        distx[i]=0;
        disty[i]=0;
        nodes[i].clear();
    }
    for(int i=0;i<n-1;i++){
        nodes[U[i]].emplace_back(V[i],W[i]);
        nodes[V[i]].emplace_back(U[i],W[i]);
    }
    dfs1(x,x,distx);
    dfs1(y,y,disty);
    
    return max(lvl1(),lvl2());
}

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