Submission #1065842

#	Time	Username	Problem	Language	Result	Execution time	Memory
1065842		vjudge1	Counting Mushrooms (IOI20_mushrooms)	C++17	80.71 / 100	11 ms	1624 KiB

mushrooms

#include "mushrooms.h"
#include <bits/stdc++.h>

using namespace std;

using vi = vector<int>;

set<int> A, B; /// indici despre care stim sigur ca sunt A sau B
int nra = 0;
set<int> PozRamase;

int get_poz() {
    int u = *PozRamase.begin();
    PozRamase.erase(u);
    return u;
}

void op1() {
    if(PozRamase.empty()) return;
    if(PozRamase.size() == 1 || (A.size() < 2 && B.size() < 2)) {
        int nou = get_poz();
        int tip = use_machine(vi{0, nou});
        if(!tip) A.insert(nou), ++nra;
        else B.insert(nou);
        return;
    }
    int p1, p2, tip;
    if(A.size() > 1) {
        p1 = *A.begin(); p2 = *A.rbegin();
        tip = 0;
    } else {
        p1 = *B.begin(); p2 = *B.rbegin();
        tip = 1;
    }

    int nou1 = get_poz(), nou2 = get_poz();

    int nr = use_machine(vi{p1, nou1, p2, nou2});

    if((nr & 1) ^ tip)
        B.insert(nou2);
    else
        A.insert(nou2), ++nra;
    if((!!(nr & 2)) ^ tip) 
        B.insert(nou1);
    else
        A.insert(nou1), ++nra;
}

void op2() {
    if(PozRamase.size() < 2) {
        op1();
        return;
    }
    int cul = 0;
    vi P;
    vi Noi;
    if(A.size() > B.size()) {
        copy(A.begin(), A.end(), back_inserter(P));
        cul = 0;
    }
    else {
        copy(B.begin(), B.end(), back_inserter(P));
        cul = 1;
    }
    while(PozRamase.size() > 1 && P.size() >= Noi.size() + 2) {
        Noi.push_back(get_poz());
    }
    P.resize(Noi.size() + 1);
    vi QRY;
    for(int i = 0; i < P.size(); ++i) {
        if(i) QRY.push_back(Noi[i - 1]);
        QRY.push_back(P[i]);
    }
    int ultp = get_poz();
    QRY.push_back(ultp);

    int nr = use_machine(QRY);

    int cul_ult = (nr & 1) ^ cul;
    if(!cul_ult) A.insert(ultp), ++nra;
    else B.insert(ultp);

    nr /= 2;

    if(!cul) nr = Noi.size() - nr;
    nra += nr;
    ///and that's about it;
}

int count_mushrooms(int n) {
    A.insert(0);
    nra = 1;
    for(int i = 1; i < n; ++i) {
        PozRamase.insert(i);
    }
    op1();
    op1();
    while(!PozRamase.empty()) op2();
    return nra;
}

Compilation message (stderr)

mushrooms.cpp: In function 'void op2()':
mushrooms.cpp:71:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   71 |     for(int i = 0; i < P.size(); ++i) {
      |                    ~~^~~~~~~~~~

• Subtask 1: 80.7143 / 100