Submission #1079783

#	Time	Username	Problem	Language	Result	Execution time	Memory
1079783		HD1	Counting Mushrooms (IOI20_mushrooms)	C++14	56.93 / 100	8 ms	600 KiB

mushrooms

#include "mushrooms.h"
#include <vector>
#include <iostream>
using namespace std;

int count_mushrooms(int n) {
    if(n < 100){
        int res = 1;
        for(int i = 2; i <= n;i++){
            int ans = use_machine({0,i-1});
            res += 1 - ans;
        }
        return res;
    }
    int k = -1,mini = 1e9;
    for(int i = 1; i < n; i++){
        int v = 2*i + ( n - (2*i + 1 ) +i)/(i+1);
        if(mini > v) mini = v, k = i;
    }
    vector<int> A,B;
    A.push_back(1);
    for(int i = 2; i <= 2*k + 1;i++){
        int ans = use_machine({0,i-1});
        if(ans == 0) A.push_back(i);
        else B.push_back(i);
    }
//    cout << k << endl;
    bool isA = true;
    int res = A.size();
    if(B.size() > A.size()) swap(A,B), isA = false;
    

    for(int i = 1; i <= ( n - (2*k + 1 ) +k)/(k+1); i++){
        int ini = 2*k+2 + (i-1)*(k+1) ;
        int fin = min(n+1, 2*k+2 + (i)*(k+1));
        vector<int> q;
//        cout <<  ini << " " << fin << endl;

        for(int j = ini; j < fin; j++){
            q.push_back(j-1);
            q.push_back(A[j-ini]-1);
        }
        
        int ans = use_machine(q);
        if(ans&1) ans = 1 + ans/2;
        else ans = ans/2;
        res += ( isA ? fin-ini-ans : ans);
        //cout << "RES: "<< res << " " << ans << endl;
    }

    //  A A B A B A -> 5 -> 2
    //  B A A A A A -> 1 -> 1 + 1/1
    //  p A p A p A ->  x -> x/2 - 
    // -> 1 +  x/2

//    cout << res << endl;
    // 1 query tenemos que un valr i -> i+1 tipos -> 2*i  -> i+1 del mismo tipo 
    // n/(i+2)  

    return res;
}

• Subtask 1: 56.927 / 100