Submission #338279

#	Time	Username	Problem	Language	Result	Execution time	Memory
338279		MvC	Counting Mushrooms (IOI20_mushrooms)	C++17	91.87 / 100	11 ms	492 KiB

mushrooms

#include "mushrooms.h"
#include <bits/stdc++.h>
#define rc(x) return cout<<x<<endl,0
#define pb push_back
#define mkp make_pair
#define in insert
#define er erase
#define fd find
#define fr first
#define sc second
#define all(x) x.begin(),x.end()
#define lun(x) (int)x.size()
typedef long long ll;
typedef long double ld;
const ll INF=0x3f3f3f3f3f3f3f3f;
const ll llinf=(1LL<<60);
const int inf=(1<<30);
const int nmax=2e4+50;
const ll mod=1e9+7;
using namespace std;
int i,j,t,x,y,rs,k;
vector<int>a[2],v;
int ask(vector<int> a)
{
    return use_machine(a);
}
int count_mushrooms(int n)
{
    if(n==2)
    {
        if(!ask({0,1}))return 2;
        return 1;
    }
    a[0].pb(0);
    if(ask({0,1}))a[1].pb(1);
    else a[0].pb(1);
    if(ask({0,2}))a[1].pb(2);
    else a[0].pb(2);
    k=105;
    for(i=3;i<n;i+=2)
    {
        if(max(lun(a[0]),lun(a[1]))>=k)break;
        v.clear();
        for(j=0;j<2;j++)
        {
            if(lun(a[j])<2)continue;
            v.pb(i),v.pb(a[j][0]);
            if(i+1<n)v.pb(i+1),v.pb(a[j][1]);
            x=ask(v);
            if(!x)
            {
                a[j].pb(i);
                if(i+1<n)a[j].pb(i+1);
            }
            else if(x==1)
            {
                a[j^1].pb(i);
                if(i+1<n)a[j].pb(i+1);
            }
            else if(x==2)
            {
                a[j].pb(i);
                a[j^1].pb(i+1);
            }
            else if(x==3)
            {
                a[j^1].pb(i);
                a[j^1].pb(i+1);
            }
            break;
        }
    }
    rs=lun(a[0]);
    for(;i<n;i+=k)
    {
        v.clear(),y=0;
        if(lun(a[0])>=lun(a[1]))k=lun(a[0]),t=0;
        else k=lun(a[1]),t=1;
        for(j=i;j<min(i+k,n);j++)
        {
            v.pb(j);
            v.pb(a[t][j-i]);
            y++;
        }
        x=ask(v);
        if(x&1)a[t^1].pb(i);
        else a[t].pb(i);
        if(t)rs+=(x+1)/2;
        else rs+=y-(x+1)/2;
    }
    return rs;
}
/*int main()
{
	//freopen("sol.in","r",stdin);
	//freopen("sol.out","w",stdout);
	//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
	ios_base::sync_with_stdio(false);cin.tie(0);cerr.tie(0);cout.tie(0);

    return 0;
}*/

• Subtask 1: 91.8699 / 100