結果

問題 No.850 企業コンテスト2位
コンテスト
ユーザー lumc_
提出日時 2019-07-05 22:31:36
言語 C++14
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 38 ms / 2,000 ms
コード長 5,869 bytes
コンパイル時間 1,651 ms
コンパイル使用メモリ 121,800 KB
実行使用メモリ 25,604 KB
平均クエリ数 200.11
最終ジャッジ日時 2024-07-16 17:23:50
合計ジャッジ時間 4,119 ms
ジャッジサーバーID
（参考情報） 		judge2 / judge1
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 1
other AC * 27
権限があれば一括ダウンロードができます

ソースコード

diff # 

// includes {{{
#include<iostream>
#include<iomanip>
#include<algorithm>
#include<vector>
#include<stack>
#include<queue>
#include<map>
#include<set>
#include<tuple>
#include<cmath>
#include<random>
#include<cassert>
#include<bitset>
#include<cstdlib>
// #include<deque>
// #include<multiset>
// #include<cstring>
// #include<bits/stdc++.h>
// }}}
using namespace std;
using ll = long long;

// #undef DEBUG
// #define DEBUG
// DEBUG {{{
#include <array>
#include <deque>
#include <iostream>
#include <list>
#include <queue>
#include <stack>
#include <tuple>
#include <valarray>
#include <vector>
template < int n, class... T >
typename std::enable_if< (n >= sizeof...(T)) >::type __output_tuple(
    std::ostream &, std::tuple< T... > const &) {}
template < int n, class... T >
typename std::enable_if< (n < sizeof...(T)) >::type __output_tuple(
    std::ostream &os, std::tuple< T... > const &t) {
  os << (n == 0 ? "" : ", ") << std::get< n >(t);
  __output_tuple< n + 1 >(os, t);
}
template < class... T >
std::ostream &operator<<(std::ostream &os, std::tuple< T... > const &t) {
  os << "(";
  __output_tuple< 0 >(os, t);
  os << ")";
  return os;
}
template < class T, class U >
std::ostream &operator<<(std::ostream &os, std::pair< T, U > const &p) {
  os << "(" << p.first << ", " << p.second << ")";
  return os;
}
template < class T >
std::ostream &operator<<(std::ostream &os, const std::stack< T > &a) {
  os << "{";
  for(auto tmp = a; tmp.size(); tmp.pop())
    os << (a.size() == tmp.size() ? "" : ", ") << tmp.top();
  os << "}";
  return os;
}
template < class T, class Container, class Compare >
std::ostream &operator<<(std::ostream &os,
    std::priority_queue< T, Container, Compare > a) {
  os << "{ (top) ";
  while(a.size()) os << a.top() << (a.size() == 1 ? "" : ", "), a.pop();
  os << " }";
  return os;
}
template < class T, class Container >
std::ostream &operator<<(std::ostream &os, std::queue< T, Container > a) {
  os << "{ ";
  while(a.size()) os << a.front() << (a.size() == 1 ? "" : ", "), a.pop();
  os << " }";
  return os;
}
#ifdef DEBUG
#if !defined(DEBUG_OUT)
#define DEBUG_OUT std::cerr
#endif
#define dump(...)                                                                \
  [&]() {                                                                        \
    auto __debug_tap = std::make_tuple(__VA_ARGS__);                             \
    DEBUG_OUT << "[" << __LINE__ << "] " << #__VA_ARGS__ << " = " << __debug_tap \
    << std::endl;                                                      \
  }()
template < class T >
inline void dump2D(T &d, size_t sizey, size_t sizex) {
  for(size_t i = 0; i < sizey; i++) {
    DEBUG_OUT << "\t";
    for(size_t j = 0; j < sizex; j++)
      DEBUG_OUT << d[i][j] << (j + 1 == sizex ? "" : "\t");
    DEBUG_OUT << std::endl;
  }
}
template < class T >
inline void dump1D(T &d, size_t sizey) {
  for(size_t i = 0; i < sizey; i++) {
    DEBUG_OUT << d[i] << (i + 1 == sizey ? "" : " ");
  }
  DEBUG_OUT << std::endl;
}
template <
class T, class = typename std::iterator_traits< decltype(begin(T())) >::value_type,
      class = typename std::enable_if< !std::is_same< T, std::string >::value >::type >
      std::ostream &operator<<(std::ostream &os, const T &a) {
        os << "{";
        for(auto ite = begin(a); ite != end(a); ++ite)
          os << (ite == begin(a) ? "" : ", ") << *ite;
        os << "}";
        return os;
      }
#else
#define dump(...) ((void) 42)
#define dump2D(...) ((void) 42)
#define dump1D(...) ((void) 42)
template <
class T, class = typename std::iterator_traits< decltype(begin(T())) >::value_type,
      class = typename std::enable_if< !std::is_same< T, std::string >::value >::type >
      std::ostream &operator<<(std::ostream &os, const T &a) {
        for(auto ite = begin(a); ite != end(a); ++ite)
          os << (ite == begin(a) ? "" : " ") << *ite;
        return os;
      }
#endif
// }}}

int n;

// 二番目に小さい

vector<int> v;
// is x < y
bool ask(int x, int y) {

#ifdef DEBUG
  static bool f = 0;
  if(!f){
    v.resize(n + 1);
    f = 1;
    iota(begin(v) + 1, end(v), 1);
    static random_device rnd;
    static mt19937 mt(rnd());
    shuffle(begin(v) + 1, end(v), mt);
    dump(v);
  }
  return v[x] < v[y];
#endif

  static int num = 0;
  num++;
  if(num > 334) assert(0);
  cout << "? " << x << " " << y << endl;
  int s;
  cin >> s;
  if(s == x) return true;
  else return false;
}

void ans(int x) {

#ifdef DEBUG
  dump(v[x]);
#endif

  cout << "! " << x << endl;
  exit(0);
}

int main() {

  // int n = 300;
  // for(int m = 2; m <= 50; m++) {
  //   int x = n - 1 + m - 1 + ceil(log2((n + m - 1) / m)) - 1;
  //   dump(m, x);
  // }
  
  cin >> n;
  
  vector<int> v(n + 1);
  iota(v.begin(), v.end(), 0);
  
  vector<int> pars;
  vector<vector<int>*> secs;
  for(int i = 1; i <= n; i += 2) {
    if(i+1 <= n) {
      if(!ask(v[i], v[i+1])) swap(v[i], v[i+1]); // v[i] < v[i+1]
      pars.push_back(v[i]);
      vector<int>* vp = new vector<int>({v[i+1]});
      secs.push_back(vp);
    } else {
      pars.push_back(v[i]);
      secs.push_back(new vector<int>);
    }
  }

  while(pars.size() >= 2) {
    assert(pars.size() == secs.size());
    int k = pars.size();
    vector<int> newpars;
    vector<vector<int>*> newsecs;
    for(int i = 0; i < k; i+=2) {
      if(i+1 < k) {
        if(!ask(pars[i], pars[i+1])) swap(pars[i], pars[i+1]), swap(secs[i], secs[i+1]); // pars[i] < pars[i+1]
        newpars.push_back(pars[i]);
        newsecs.push_back(secs[i]);
        newsecs.back()->push_back(pars[i+1]);
      } else {
        newpars.push_back(pars[i]);
        newsecs.push_back(secs[i]);
      }
    }
    pars = newpars;
    secs = newsecs;
  }

  int mini = n + 1;
  for(auto e : *secs.back()) {
    if(mini == n + 1) mini = e;
    else mini = ask(mini, e) ? mini : e;
  }

  ans(mini);

  return 0;
}
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