Submission #307807

#	Time	Username	Problem	Language	Result	Execution time	Memory
307807		CodePlatina	Counting Mushrooms (IOI20_mushrooms)	C++14	69.54 / 100	14 ms	512 KiB

mushrooms

#include "mushrooms.h"
#include <vector>

using namespace std;

int count_mushrooms(int n)
{
    if(n <= 452)
    {
        int ret = 1;
        for(int i = 1; i < n; i += 2)
        {
            if(i == n - 1) ret += 1 - use_machine({0, i});
            else ret += 2 - use_machine({i, 0, i + 1});
        }
        return ret;
    }
    else
    {
        int ret = 1;
        vector<int> A, B, C;
        A.push_back(0);
        for(int i = 1; i < n; ++i) C.push_back(i);
        while(A.size() < 116 && B.size() < 116)
        {
            if(B.empty() || B.size() > A.size())
            {
                int x = C.back(); C.pop_back();
                int y = C.back(); C.pop_back();
                int t = use_machine({A[0], x, y});
                if(t == 0)
                {
                    A.push_back(x);
                    A.push_back(y);
                    ret += 2;
                }
                else if(t == 1)
                {
                    B.push_back(y);
                    C.push_back(x);
                }
                else if(t == 2)
                {
                    A.push_back(y);
                    B.push_back(x);
                    ret += 1;
                }
            }
            else
            {
                int x = C.back(); C.pop_back();
                int y = C.back(); C.pop_back();
                int t = use_machine({B[0], x, y});
                if(t == 0)
                {
                    B.push_back(x);
                    B.push_back(y);
                }
                else if(t == 1)
                {
                    A.push_back(y);
                    C.push_back(x);
                    ret += 1;
                }
                else if(t == 2)
                {
                    A.push_back(x);
                    B.push_back(y);
                    ret += 1;
                }
            }
        }
        if(A.size() >= B.size())
        {
            for(int i = 0; i < (int)C.size(); i += (int)A.size())
            {
                int cnt = 0;
                vector<int> tmp;
                for(int j = i; j < (int)C.size() && j < i + (int)A.size(); ++j)
                {
                    ++cnt;
                    tmp.push_back(A[j - i]);
                    tmp.push_back(C[j]);
                }
                int t = use_machine(tmp);
                if(t & 1) ++t;
                t /= 2;
                ret += cnt - t;
            }
        }
        else
        {
            swap(A, B);
            for(int i = 0; i < (int)C.size(); i += (int)A.size())
            {
                int cnt = 0;
                vector<int> tmp;
                for(int j = i; j < (int)C.size() && j < i + (int)A.size(); ++j)
                {
                    ++cnt;
                    tmp.push_back(A[j - i]);
                    tmp.push_back(C[j]);
                }
                int t = use_machine(tmp);
                if(t & 1) ++t;
                t /= 2;
                ret += t;
            }
        }
        return ret;
    }
}

• Subtask 1: 69.5385 / 100