Submission #1293387

#	Time	Username	Problem	Language	Result	Execution time	Memory
1293387		lambd47	버섯 세기 (IOI20_mushrooms)	C++20	91.87 / 100	4 ms	992 KiB

mushrooms

#include<bits/stdc++.h>
#include "mushrooms.h"
using namespace std;

#define ll long long
#define sz(v) ((int)(v).size())
#define all(v) (v).begin(), (v).end()
#define L(i, j, k) for(int i = (j); i <= (k); ++i)
#define R(i, j, k) for(int i = (j); i >= (k); --i)


int count_mushrooms(int n) {
    vector<int> ids(n-1);
    iota(all(ids),1);
    reverse(all(ids));
    vector<int> tipo[2];
    vector<vector<int>> adj(n);
    tipo[0].clear();tipo[1].clear();
    tipo[0].push_back(0);
    vector<int> aux;
    int resp=0;
    vector<int> fila;
    while(!ids.empty() && sz(tipo[0])<3 && sz(tipo[1])<3){
        aux.clear();
        aux.push_back(0);
        aux.push_back(ids.back());
        int v=use_machine(aux);
        tipo[v].push_back(ids.back());
        ids.pop_back();
    }
    auto dfs=[&](auto&& self, int node,int pai,int at)->void{
        tipo[at].push_back(node);
        for(auto a:adj[node]){
            if(a==pai)continue;
            self(self,a,node,at^1);
        }
    };

    auto op=[&](int a,int b, int c, int at)->void{
        aux.clear();
        aux={tipo[at][0],a,tipo[at][1],b,tipo[at][2],c};
        int v=use_machine(aux);
        if(v&1){
            dfs(dfs,c,c,at^1);
            v--;
        }
        else dfs(dfs,c,c,at);
        if(v==4){
            dfs(dfs,a,a,at^1);
            dfs(dfs,b,b,at^1);
        }
        else if(v==2){
            adj[a].push_back(b);
            fila.push_back(a);
        }
        else{
            dfs(dfs,a,a,at);
            dfs(dfs,b,b,at);
        }
    };
    int at=0;
    if(sz(tipo[1])>=3)at=1;
    int m=80;
    while(sz(ids)+sz(fila)>2 && sz(tipo[0])<m && sz(tipo[1])<m){
        while(sz(fila)<3){
            fila.push_back(ids.back());
            ids.pop_back();
        }
        int a=fila.back();fila.pop_back();
        int b=fila.back();fila.pop_back();
        int c=fila.back();fila.pop_back();
        op(a,b,c,at);
    }
    if(sz(ids)<=2){
        while(sz(ids)>0){
            fila.push_back(ids.back());
            ids.pop_back();
        }
    }
    for(auto a:fila){
        aux.clear();aux={0,a};
        dfs(dfs,a,a,use_machine(aux));
    }
    if(sz(ids)==0){
        return resp+sz(tipo[0]);
    }

    at=0;
    if(sz(tipo[1])>=sz(tipo[0]))at=1;

    while(!ids.empty()){
        int vida=sz(tipo[at])-1;
        aux.clear();
        while(vida>=0 && !ids.empty()){
            aux.push_back(tipo[at][vida]);
            aux.push_back(ids.back());
            ids.pop_back();
            vida--;
        }
        int v=use_machine(aux);
        int oposto=0;
        if(v&1){
            v++;
            oposto=1;
        }
        if(at==1){
            resp+=v/2;
            if(oposto==1){
                resp--;
                tipo[0].push_back(aux.back());
            }
            else{
                tipo[1].push_back(aux.back());
            }
        }
        else{
            resp+=sz(aux)/2-v/2;
            if(oposto==1){
                tipo[1].push_back(aux.back());
            }
            else{
                tipo[0].push_back(aux.back());
                resp--;
            }
        }
        if(sz(tipo[at^1])>sz(tipo[at]))at^=1;
    }
    return resp+sz(tipo[0]);
}

• Subtask 1: 91.8699 / 100