Problem p02649 (C++) — buggy submission, verdict: Time Limit Exceeded

#include <algorithm>
#include <cassert>
#include <chrono>
#include <cmath>
#include <cstdio>
#include <ctime>
#include <functional>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <string>
#include <tuple>
#include <utility>
#include <vector>
using namespace std;

namespace {
using Integer = long long; //__int128;
template <class T, class S> istream &operator>>(istream &is, pair<T, S> &p) {
  return is >> p.first >> p.second;
}
template <class T> istream &operator>>(istream &is, vector<T> &vec) {
  for (T &val : vec)
    is >> val;
  return is;
}
template <class T> istream &operator,(istream &is, T &val) { return is >> val; }
template <class T, class S>
ostream &operator<<(ostream &os, const pair<T, S> &p) {
  return os << p.first << " " << p.second;
}
template <class T> ostream &operator<<(ostream &os, const vector<T> &vec) {
  for (size_t i = 0; i < vec.size(); i++)
    os << vec[i] << (i == vec.size() - 1 ? "" : " ");
  return os;
}
template <class T> ostream &operator,(ostream &os, const T &val) {
  return os << " " << val;
}

template <class H> void print(const H &head) { cout << head; }
template <class H, class... T> void print(const H &head, const T &...tail) {
  cout << head << " ";
  print(tail...);
}
template <class... T> void println(const T &...values) {
  print(values...);
  cout << endl;
}

template <class H> void eprint(const H &head) { cerr << head; }
template <class H, class... T> void eprint(const H &head, const T &...tail) {
  cerr << head << " ";
  eprint(tail...);
}
template <class... T> void eprintln(const T &...values) {
  eprint(values...);
  cerr << endl;
}

class range {
  Integer start_, end_, step_;

public:
  struct range_iterator {
    Integer val, step_;
    range_iterator(Integer v, Integer step) : val(v), step_(step) {}
    Integer operator*() { return val; }
    void operator++() { val += step_; }
    bool operator!=(range_iterator &x) {
      return step_ > 0 ? val < x.val : val > x.val;
    }
  };
  range(Integer len) : start_(0), end_(len), step_(1) {}
  range(Integer start, Integer end) : start_(start), end_(end), step_(1) {}
  range(Integer start, Integer end, Integer step)
      : start_(start), end_(end), step_(step) {}
  range_iterator begin() { return range_iterator(start_, step_); }
  range_iterator end() { return range_iterator(end_, step_); }
};

inline string operator"" _s(const char *str, size_t size) {
  return move(string(str));
}
constexpr Integer my_pow(Integer x, Integer k, Integer z = 1) {
  return k == 0    ? z
         : k == 1  ? z * x
         : (k & 1) ? my_pow(x * x, k >> 1, z * x)
                   : my_pow(x * x, k >> 1, z);
}
constexpr Integer my_pow_mod(Integer x, Integer k, Integer M, Integer z = 1) {
  return k == 0    ? z % M
         : k == 1  ? z * x % M
         : (k & 1) ? my_pow_mod(x * x % M, k >> 1, M, z * x % M)
                   : my_pow_mod(x * x % M, k >> 1, M, z);
}
constexpr unsigned long long operator"" _ten(unsigned long long value) {
  return my_pow(10, value);
}

inline int k_bit(Integer x, int k) { return (x >> k) & 1; } // 0-indexed

// mt19937
// mt(chrono::duration_cast<chrono::nanoseconds>(chrono::steady_clock::now().time_since_epoch()).count());
mt19937 mt(1);

template <class T> string join(const vector<T> &v, const string &sep) {
  stringstream ss;
  for (size_t i = 0; i < v.size(); i++) {
    if (i > 0)
      ss << sep;
    ss << v[i];
  }
  return ss.str();
}

inline string operator*(string s, int k) {
  string ret;
  while (k) {
    if (k & 1)
      ret += s;
    s += s;
    k >>= 1;
  }
  return ret;
}
} // namespace
constexpr long long mod = 9_ten + 7;

#include <unordered_map>

int main() {
  long long n, k, s, t;
  cin >> n, k, s, t;
  vector<long long> a(n);
  cin >> a;

  constexpr long long shift = 18;

  long long mask = (1ll << shift) - 1;
  long long ans = 0;

  auto get_state = [&](long long v) {
    long long state_or = v & mask;
    long long state_and = (~v) & mask;
    return (state_or << shift) | state_and;
  };

  long long goal = (t << shift) | ((~s) & mask);

  vector<unordered_map<long long, long long>> dp(k + 1);
  dp[0][0] = 1;
  for (int j = 0; j < n; j++) {
    long long u = get_state(a[j]);
    for (int f = (int)dp.size() - 2; f >= 0; f--) {
      if (dp[f].size() == 0)
        continue;
      for (auto v : dp[f]) {
        dp[f + 1][v.first | u] += v.second;
      }
    }
  }

  for (int f = 0; f <= k; f++) {
    ans += dp[f][goal];
  }
  println(ans);

  // auto naive = [&]() -> long long{
  //   long long res = 0;
  //   if(c.size() == 0){
  //     return 0;
  //   }
  //   vector<long long> dp_s(1<<c.size(), -1);
  //   vector<long long> dp_t(1<<c.size(),  0);
  //   for(int i=0; i<c.size(); i++){
  //     dp_s[1<<i] = c[i];
  //     dp_t[1<<i] = c[i];
  //   }

  //   for(int i=1; i<(1<<c.size()); i++){
  //     for(int j=0; j<c.size(); j++){
  //       if((i>>j) & 1) continue;
  //       dp_s[i|(1<<j)] = dp_s[i] & c[j];
  //       dp_t[i|(1<<j)] = dp_t[i] | c[j];
  //     }

  //     if(dp_s[i] == s && dp_t[i] == t && __builtin_popcountll(i) <= k){
  //       res++;
  //     }
  //   }
  //   return res;
  // };

  // println(naive());

  return 0;
}


Error: TLE

Fixed submission:

#include <algorithm>
#include <cassert>
#include <chrono>
#include <cmath>
#include <cstdio>
#include <ctime>
#include <functional>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <string>
#include <tuple>
#include <utility>
#include <vector>
using namespace std;

namespace {
using Integer = long long; //__int128;
template <class T, class S> istream &operator>>(istream &is, pair<T, S> &p) {
  return is >> p.first >> p.second;
}
template <class T> istream &operator>>(istream &is, vector<T> &vec) {
  for (T &val : vec)
    is >> val;
  return is;
}
template <class T> istream &operator,(istream &is, T &val) { return is >> val; }
template <class T, class S>
ostream &operator<<(ostream &os, const pair<T, S> &p) {
  return os << p.first << " " << p.second;
}
template <class T> ostream &operator<<(ostream &os, const vector<T> &vec) {
  for (size_t i = 0; i < vec.size(); i++)
    os << vec[i] << (i == vec.size() - 1 ? "" : " ");
  return os;
}
template <class T> ostream &operator,(ostream &os, const T &val) {
  return os << " " << val;
}

template <class H> void print(const H &head) { cout << head; }
template <class H, class... T> void print(const H &head, const T &...tail) {
  cout << head << " ";
  print(tail...);
}
template <class... T> void println(const T &...values) {
  print(values...);
  cout << endl;
}

template <class H> void eprint(const H &head) { cerr << head; }
template <class H, class... T> void eprint(const H &head, const T &...tail) {
  cerr << head << " ";
  eprint(tail...);
}
template <class... T> void eprintln(const T &...values) {
  eprint(values...);
  cerr << endl;
}

class range {
  Integer start_, end_, step_;

public:
  struct range_iterator {
    Integer val, step_;
    range_iterator(Integer v, Integer step) : val(v), step_(step) {}
    Integer operator*() { return val; }
    void operator++() { val += step_; }
    bool operator!=(range_iterator &x) {
      return step_ > 0 ? val < x.val : val > x.val;
    }
  };
  range(Integer len) : start_(0), end_(len), step_(1) {}
  range(Integer start, Integer end) : start_(start), end_(end), step_(1) {}
  range(Integer start, Integer end, Integer step)
      : start_(start), end_(end), step_(step) {}
  range_iterator begin() { return range_iterator(start_, step_); }
  range_iterator end() { return range_iterator(end_, step_); }
};

inline string operator"" _s(const char *str, size_t size) {
  return move(string(str));
}
constexpr Integer my_pow(Integer x, Integer k, Integer z = 1) {
  return k == 0    ? z
         : k == 1  ? z * x
         : (k & 1) ? my_pow(x * x, k >> 1, z * x)
                   : my_pow(x * x, k >> 1, z);
}
constexpr Integer my_pow_mod(Integer x, Integer k, Integer M, Integer z = 1) {
  return k == 0    ? z % M
         : k == 1  ? z * x % M
         : (k & 1) ? my_pow_mod(x * x % M, k >> 1, M, z * x % M)
                   : my_pow_mod(x * x % M, k >> 1, M, z);
}
constexpr unsigned long long operator"" _ten(unsigned long long value) {
  return my_pow(10, value);
}

inline int k_bit(Integer x, int k) { return (x >> k) & 1; } // 0-indexed

// mt19937
// mt(chrono::duration_cast<chrono::nanoseconds>(chrono::steady_clock::now().time_since_epoch()).count());
mt19937 mt(1);

template <class T> string join(const vector<T> &v, const string &sep) {
  stringstream ss;
  for (size_t i = 0; i < v.size(); i++) {
    if (i > 0)
      ss << sep;
    ss << v[i];
  }
  return ss.str();
}

inline string operator*(string s, int k) {
  string ret;
  while (k) {
    if (k & 1)
      ret += s;
    s += s;
    k >>= 1;
  }
  return ret;
}
} // namespace
constexpr long long mod = 9_ten + 7;

int main() {
  long long n, k, s, t;
  cin >> n, k, s, t;
  vector<long long> a(n);
  cin >> a;

  constexpr long long shift = 18;

  long long mask = (1ll << shift) - 1;
  long long ans = 0;

  auto get_state = [&](long long v) {
    long long state_or = v & mask;
    long long state_and = (~v) & mask;
    return (state_or << shift) | state_and;
  };

  long long goal = (t << shift) | ((~s) & mask);

  vector<map<long long, long long>> dp(k + 1);
  dp[0][0] = 1;
  for (int j = 0; j < n; j++) {
    long long u = get_state(a[j]);
    for (int f = (int)dp.size() - 2; f >= 0; f--) {
      if (dp[f].size() == 0)
        continue;
      for (auto v : dp[f]) {
        dp[f + 1][v.first | u] += v.second;
      }
    }
  }

  for (int f = 0; f <= k; f++) {
    ans += dp[f][goal];
  }
  println(ans);

  // auto naive = [&]() -> long long{
  //   long long res = 0;
  //   if(c.size() == 0){
  //     return 0;
  //   }
  //   vector<long long> dp_s(1<<c.size(), -1);
  //   vector<long long> dp_t(1<<c.size(),  0);
  //   for(int i=0; i<c.size(); i++){
  //     dp_s[1<<i] = c[i];
  //     dp_t[1<<i] = c[i];
  //   }

  //   for(int i=1; i<(1<<c.size()); i++){
  //     for(int j=0; j<c.size(); j++){
  //       if((i>>j) & 1) continue;
  //       dp_s[i|(1<<j)] = dp_s[i] & c[j];
  //       dp_t[i|(1<<j)] = dp_t[i] | c[j];
  //     }

  //     if(dp_s[i] == s && dp_t[i] == t && __builtin_popcountll(i) <= k){
  //       res++;
  //     }
  //   }
  //   return res;
  // };

  // println(naive());

  return 0;
}