Submission #1052330

#	Time	Username	Problem	Language	Result	Execution time	Memory
1052330		epicci23	Counting Mushrooms (IOI20_mushrooms)	C++17	80.43 / 100	5 ms	600 KiB

mushrooms

#include "bits/stdc++.h"
//#define int long long
#define all(v) v.begin() , v.end()
#define sz(a) (int)a.size()
#include "mushrooms.h"
using namespace std;

const int S = 142;

int count_mushrooms(int n){
  vector<int> v[2];
  int ansA=0;
  v[0].push_back(0);
  for(int i=1;i<n;){
    if(i==n-1){
      if(use_machine({0,i})) v[1].push_back(i);
      else v[0].push_back(i);
      i++;
      break;
    }
    if(sz(v[0])<2 && sz(v[1])<2){
      if(use_machine({0,i})) v[1].push_back(i);
      else v[0].push_back(i);
      i++;
      continue;
    }
    else if(sz(v[0])<S && sz(v[1])<S){
      if(sz(v[0])>=2){
        int res = use_machine({v[0][0],i,v[0][1],i+1});
        if(res&1) v[1].push_back(i+1);
        else v[0].push_back(i+1);
        if(res&2) v[1].push_back(i);
        else v[0].push_back(i);
        i+=2;
      }
      else{
        int res = use_machine({v[1][0],i,v[1][1],i+1});
        if(res&1) v[0].push_back(i+1);
        else v[1].push_back(i+1);
        if(res&2) v[0].push_back(i);
        else v[1].push_back(i);
        i+=2;
      }
      continue;
    }
    else{
      if(sz(v[0])>=S){
        vector<int> cur;
        cur.push_back(v[0][0]);
        int p=1;
        while(i<n-1 && p<S){
          cur.push_back(i++);
          cur.push_back(v[0][p++]);
        }
        cur.push_back(i++);
        int res=use_machine(cur);
        if(!(res&1)) ansA++;
        ansA+=sz(cur)/2-1-res/2;
      }
      else{
        vector<int> cur;
        cur.push_back(v[1][0]);
        int p=1;
        while(i<n-1 && p<S){
          cur.push_back(i++);
          cur.push_back(v[1][p++]);
        }
        cur.push_back(i++);
        int res=use_machine(cur);
        if(res&1) ansA++;
        ansA+=res/2;
      }
    }
  }
  return sz(v[0]) + ansA;
}

• Subtask 1: 80.427 / 100