Submission #304796

#	Time	Username	Problem	Language	Result	Execution time	Memory
304796		Fdg	Counting Mushrooms (IOI20_mushrooms)	C++14	100 / 100	10 ms	768 KiB

mushrooms

#include <iostream>
#include <vector>
#include <map>
#include <set>
#include <algorithm>
#include "mushrooms.h"

using namespace std;

const int VAL = 100;

vector<int> a, b;

void process(int x, bool isA) {
  if (isA) a.push_back(x);
  else b.push_back(x);
}

int count_mushrooms(int n) {
  a.clear(); b.clear();

  vector<int> v;
  for (int i = 1; i < n; ++i)
    v.push_back(i);

  int ans = 0, pos = 0;

  a.push_back(0);
  while (a.size() < VAL && b.size() < VAL && pos + 5 <= (int) v.size()) {
    if (a.size() > 2 && b.size() > 1) {
      vector<int> arr;
      arr.push_back(a[0]);
      arr.push_back(v[pos]), ++pos;
      arr.push_back(a[1]);
      arr.push_back(v[pos]), ++pos; 
      arr.push_back(a[2]);
      arr.push_back(v[pos]), ++pos; 

      int ret = use_machine(arr);
      if (ret == 5) {
        process(arr[1], false);
        process(arr[3], false);
        process(arr[5], false);
      } else if (ret == 4) {
        process(arr[1], false);
        process(arr[3], false);
        process(arr[5], true);
      } else if (ret == 3) {
        process(arr[5], false);
        vector<int> nArr = {b[1], arr[1], b[0], a[0], arr[3], a[1]};
        nArr.push_back(v[pos]), ++pos;
        nArr.push_back(a[2]);
        nArr.push_back(v[pos]), ++pos;

        int cur = use_machine(nArr) - 1;
        process(arr[1], (cur & 4));
        process(arr[3], !(cur & 4));
        process(nArr[6], !(cur & 2));
        process(nArr[8], !(cur & 1));
      } else if (ret == 2) {
        process(arr[5], true);
        vector<int> nArr = {b[1], arr[1], b[0], a[0], arr[3], a[1]};
        nArr.push_back(v[pos]), ++pos;
        nArr.push_back(a[2]);
        nArr.push_back(v[pos]), ++pos;

        int cur = use_machine(nArr) - 1;
        process(arr[1], (cur & 4));
        process(arr[3], !(cur & 4));
        process(nArr[6], !(cur & 2));
        process(nArr[8], !(cur & 1));
      } else if (ret == 1) {
        process(arr[1], true);
        process(arr[3], true);
        process(arr[5], false);
      } else {
        process(arr[1], true);
        process(arr[3], true);
        process(arr[5], true);
      }
    } else if (b.size() > 2 && a.size() > 1) {
      vector<int> arr;
      arr.push_back(b[0]);
      arr.push_back(v[pos]), ++pos;
      arr.push_back(b[1]);
      arr.push_back(v[pos]), ++pos; 
      arr.push_back(b[2]);
      arr.push_back(v[pos]), ++pos; 

      int ret = use_machine(arr);
      if (ret == 5) {
        process(arr[1], true);
        process(arr[3], true);
        process(arr[5], true);
      } else if (ret == 4) {
        process(arr[1], true);
        process(arr[3], true);
        process(arr[5], false);
      } else if (ret == 3) {
        process(arr[5], true);
        vector<int> nArr = {a[1], arr[1], a[0], b[0], arr[3], b[1]};
        nArr.push_back(v[pos]), ++pos;
        nArr.push_back(b[2]);
        nArr.push_back(v[pos]), ++pos;

        int cur = use_machine(nArr) - 1;
        process(arr[1], !(cur & 4));
        process(arr[3], (cur & 4));
        process(nArr[6], (cur & 2));
        process(nArr[8], (cur & 1));
      } else if (ret == 2) {
        process(arr[5], false);
        vector<int> nArr = {a[1], arr[1], a[0], b[0], arr[3], b[1]};
        nArr.push_back(v[pos]), ++pos;
        nArr.push_back(b[2]);
        nArr.push_back(v[pos]), ++pos;
      
        int cur = use_machine(nArr) - 1;
        process(arr[1], !(cur & 4));
        process(arr[3], (cur & 4));
        process(nArr[6], (cur & 2));
        process(nArr[8], (cur & 1));
      } else if (ret == 1) {
        process(arr[1], false);
        process(arr[3], false);
        process(arr[5], true);
      } else {
        process(arr[1], false);
        process(arr[3], false);
        process(arr[5], false);
      }
    } else if (a.size() > 1) {
      vector<int> arr;
      arr.push_back(v[pos]), ++pos;
      arr.push_back(a[0]);
      arr.push_back(v[pos]), ++pos;
      arr.push_back(a[1]); 
 
      int ret = use_machine(arr);
      if (ret == 3) {
        process(arr[0], false);
        process(arr[2], false);
      } else if (ret == 2) {
        process(arr[0], true);
        process(arr[2], false);
      } else if (ret == 1) {
        process(arr[0], false);
        process(arr[2], true); 
      } else {
        process(arr[0], true);
        process(arr[2], true);
      }
    } else if (b.size() > 1) {
      vector<int> arr;
      arr.push_back(v[pos]), ++pos;
      arr.push_back(b[0]);
      arr.push_back(v[pos]), ++pos;
      arr.push_back(b[1]); 
 
      int ret = use_machine(arr);
      if (ret == 3) {
        process(arr[0], true);
        process(arr[2], true);
      } else if (ret == 2) {
        process(arr[0], false);
        process(arr[2], true);
      } else if (ret == 1) {
        process(arr[0], true);
        process(arr[2], false); 
      } else {
        process(arr[0], false);
        process(arr[2], false);
      }
    } else {
      vector<int> arr = {a[0]};
      arr.push_back(v[pos]), ++pos;

      int ret = use_machine(arr);
      if (ret & 1) {
        process(arr[1], false);
      } else {
        process(arr[1], true);
      }
    }
  }

  ans = a.size();
  while (pos < (int) v.size()) {
    if (a.size() >= b.size()) {
      vector<int> arr;
      int used = 0;
      for (int i = 0; i < (int) a.size(); ++i) {
        arr.push_back(a[i]);
        if (pos < (int) v.size()) {
          arr.push_back(v[pos]), ++pos;
          ++used;
        } else break;
      }
      int ret = use_machine(arr);
      int diff = (ret / 2) + (ret & 1);
      ans += used - diff;
      if (ret & 1) {
        b.push_back(arr.back());
      } else {
        a.push_back(arr.back());
      }
    } else {
      vector<int> arr;
      int used = 0;
      for (int i = 0; i < (int) b.size(); ++i) {
        arr.push_back(b[i]);
        if (pos < (int) v.size()) {
          arr.push_back(v[pos]), ++pos;
          ++used;
        } else break;
      }
      int ret = use_machine(arr);
      int diff = (ret / 2) + (ret & 1);
      ans += diff;
      if (ret & 1) {
        a.push_back(arr.back());
      } else {
        b.push_back(arr.back());
      }
    }
  }

  return ans;
}

• Subtask 1: 100 / 100