Submission #1190910

#TimeUsernameProblemLanguageResultExecution timeMemory
1190910avighnaToxic Gene (NOI23_toxic)C++20
62.20 / 100
7 ms496 KiB
#include "toxic.h"
#include <algorithm>
#include <cassert>
#include <functional>
#include <iostream>
#include <numeric>
#include <random>
#include <ranges>

int BinarySearchMin(int s, int e, const std::function<bool(int)> &f) {
  while (s < e) {
    int m = s + (e - s) / 2;
    if (f(m)) {
      e = m;
    } else {
      s = m + 1;
    }
  }
  return s;
}

void determine_type(int n) {
  std::vector<char> ans(n + 1);

  std::vector<int> p(n);
  std::iota(p.begin(), p.end(), 0);
  std::random_device rd;
  std::mt19937 gen(rd());
  std::shuffle(p.begin(), p.end(), gen);

  // with randomized index locs, new funcs
  auto query = [&](std::vector<int> sample) {
    for (auto &i : sample) {
      i = p[i - 1] + 1;
    }
    return query_sample(sample);
  };
  auto answer = [&](int i, char x) { answer_type(p[i - 1] + 1, x); };

  auto create_vec = [](int s, int e) {
    std::vector<int> ans;
    for (int i = s; i <= e; ++i) {
      ans.push_back(i);
    }
    return ans;
  };

  auto create_sample = [&](std::vector<int>::iterator begin,
                           std::vector<int>::iterator end) {
    std::vector<int> sample;
    for (int bt = 0; bt < 8 and begin != end; ++bt, ++begin) {
      for (int j = 0; j < (1 << bt); ++j) {
        sample.push_back(*begin);
      }
    }
    return sample;
  };

  std::vector<int> check; // normal, strong
  std::vector<int> naturals(n + 1);
  std::iota(naturals.begin(), naturals.end(), 0);
  int toxic_loc = 0;
  for (int i = 1; i <= n; i += 8) {
    auto sample = create_sample(naturals.begin() + i,
                                naturals.begin() + std::min(n + 1, i + 8));
    int mask = query(sample);
    if (mask == sample.size()) {
      for (int j = i; j <= std::min(n, i + 7); ++j) {
        check.push_back(j);
      }
    } else {
      std::vector<int> idxs;
      for (int j = i, bt = 0; j <= std::min(n, i + 7); ++j, ++bt) {
        if (mask & (1 << bt)) {
          ans[j] = 'S';
        } else {
          idxs.push_back(j);
        }
      }
      do {
        int pt = BinarySearchMin(0, idxs.size() - 1, [&](int j) {
          std::vector<int> sample;
          for (int k = 0; k <= j; ++k) {
            sample.push_back(idxs[k]);
          }
          return query(sample) != j + 1;
        });
        ans[idxs[pt]] = 'T';
        toxic_loc = idxs[pt];
        idxs.erase(idxs.begin() + pt);
        std::sort(idxs.begin(), idxs.end());
      } while (query(idxs) != idxs.size());
      for (int i = 0; i < idxs.size(); ++i) {
        ans[idxs[i]] = 'R';
      }
    }
  }

  for (int i = 0; i < check.size(); i += 8) {
    auto sample = create_sample(
        check.begin() + i, check.begin() + std::min(int(check.size()), i + 8));
    sample.push_back(toxic_loc);
    auto mask = query(sample);
    for (int bt = 0; bt < 8 and i + bt < check.size(); ++bt) {
      if (mask & (1 << bt)) {
        ans[check[i + bt]] = 'S';
      } else {
        ans[check[i + bt]] = 'R';
      }
    }
  }

  for (int i = 1; i <= n; ++i) {
    answer(i, ans[i]);
  }
}
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