Submission #898999

#	Time	Username	Problem	Language	Result	Execution time	Memory
898999		abcvuitunggio	Counting Mushrooms (IOI20_mushrooms)	C++17	92.62 / 100	5 ms	720 KiB

mushrooms

#include "mushrooms.h"
#include <bits/stdc++.h>
using namespace std;
const int k=90;
vector <int> a,b;
int t,res,sz;
int count_mushrooms(int n){
	if (n<=227){
        for (int i=1;i<n;i++)
            res+=1-use_machine({0,i});
        return res+1;
	}
	a.push_back(0);
	for (int i=1;i<=2;i++){
        int x=use_machine({0,i});
        if (x)
            b.push_back(i);
        else
            a.push_back(i);
	}
	for (int i=3;;i+=2){
        if (max(a.size(),b.size())>=k)
            break;
        if (a.size()>1){
            int x=use_machine({i,a[0],i+1,a[1]});
            if (x&1)
                b.push_back(i);
            else
                a.push_back(i);
            if ((x>>1)&1)
                b.push_back(i+1);
            else
                a.push_back(i+1);
            continue;
        }
        int x=use_machine({i,b[0],i+1,b[1]});
        if (x&1)
            a.push_back(i);
        else
            b.push_back(i);
        if ((x>>1)&1)
            a.push_back(i+1);
        else
            b.push_back(i+1);
	}
	t=(a.size()<k);
	if (a.size()<k)
        swap(a,b);
    res=b.size();
	for (int i=a.size()+b.size();i<n;){
        if (i==n-1){
            res+=abs(t-use_machine({0,i}));
            break;
        }
        vector <int> ve;
        for (int j=i;j<min(i+(int)a.size(),n);j++){
            ve.push_back(j);
            ve.push_back(a[j-i]);
        }
        int x=use_machine(ve);
        res+=(x+1)/2;
        if (x&1)
            b.push_back(i);
        else
            a.push_back(i);
        if (a.size()<b.size()){
            res=min(i+(int)a.size(),n)-res;
            swap(a,b);
            t^=1;
        }
        i=ve[ve.size()-2]+1;
	}
	return (t?res:n-res);
}

• Subtask 1: 92.623 / 100