#755742 (C++17(gcc12)) No.1909 Detect from Substrings

• 問題: No.1909 Detect from Substrings
• ユーザー: keijak
• 提出日時: 2022-04-23 09:40:13
• 言語: C++17(gcc12) (gcc 12.4.0 + boost 1.89.0)
• 結果: TLE
• 実行時間: -
• コード長: 8,010 bytes
• コンパイル時間: 1,873 ms
• コンパイル使用メモリ: 229,072 KB
• 実行使用メモリ: 13,184 KB
• 最終ジャッジ日時: 2026-06-25 19:57:06
• 合計ジャッジ時間: 8,864 ms
• ジャッジサーバーID （参考情報）: judge1_0 / judge2_0

ファイルパターン	結果
sample	AC * 3
other	AC * 2 TLE * 2 -- * 32

ソースコード

#include <bits/stdc++.h>
#define REP_(i, a_, b_, a, b, ...) for (int i = (a), END_##i = (b); i < END_##i; ++i)
#define REP(i, ...) REP_(i, __VA_ARGS__, __VA_ARGS__, 0, __VA_ARGS__)
#define ALL(x) std::begin(x), std::end(x)
using Int = long long;
using Uint = unsigned long long;
using Real = long double;

template<typename T, typename U>
inline bool chmax(T &a, U b) { return a < b and ((a = b), true); }
template<typename T, typename U>
inline bool chmin(T &a, U b) { return a > b and ((a = b), true); }
template<typename T>
inline int ssize(const T &a) { return (int) a.size(); }
template<typename T>
constexpr T kBigVal = std::numeric_limits<T>::max() / 2;

struct CastInput {
  template<typename T>
  operator T() const {
    T x;
    std::cin >> x;
    return x;
  }
  struct Sized {
    int n;
    template<typename T>
    operator T() const {
      T xs(n);
      for (auto &x: xs) std::cin >> x;
      return xs;
    }
  };
  Sized operator()(int n) const { return {n}; }
} in;

template<typename Container>
std::ostream &print_seq(const Container &seq,
                        const char *sep = " ",
                        const char *ends = "\n",
                        std::ostream &os = std::cout) {
  const auto itl = std::begin(seq), itr = std::end(seq);
  for (auto it = itl; it != itr; ++it) {
    if (it != itl) os << sep;
    os << *it;
  }
  return os << ends;
}

template<typename T>
inline std::ostream &print_one(const T &x, char endc) {
  if constexpr (std::is_same<T, bool>::value) {
    return std::cout << (x ? "Yes" : "No") << endc;
  } else {
    return std::cout << x << endc;
  }
}
template<typename T>
inline std::ostream &print(const T &x) { return print_one(x, '\n'); }
template<typename T, typename... Ts>
std::ostream &print(const T &head, Ts... tail) {
  return print_one(head, ' '), print(tail...);
}
inline std::ostream &print() { return std::cout << '\n'; }
void exit_() { std::cout.flush(), std::cerr.flush(), std::_Exit(0); }

#ifdef MY_DEBUG
#include "debug_dump.hpp"
#include "backward.hpp"
backward::SignalHandling kSignalHandling;
#else
#define DUMP(...)
#define cerr if(false)cerr
#endif

using namespace std;

struct RollingHash {
  using u64 = std::uint64_t;
  using u128 = __uint128_t;
  static const u64 kMod = (1ULL << 61) - 1;

  static u64 base() {
    static const u64 kBase = []() {
      std::mt19937_64 engine(std::random_device{}());
      std::uniform_int_distribution<u64> rand(1000, kMod - 1);
      return rand(engine);
    }();
    return kBase;
  }

  static inline u64 add(u64 a, u64 b) {
    a += b;
    return (a >= kMod) ? (a - kMod) : a;
  }

  static inline u64 sub(u64 a, u64 b) { return add(a, kMod - b); }

  static inline u64 mul(u64 a, u64 b) {
    u128 t = u128(a) * b;
    u64 na = u64(t >> 61);
    u64 nb = u64(t & kMod);
    na += nb;
    return (na >= kMod) ? (na - kMod) : na;
  }

  static u64 pow_base(int i) {
    static std::vector<u64> kPowBase(1, 1);
    while (int(kPowBase.size()) <= i) {
      u64 val = mul(kPowBase.back(), base());
      kPowBase.push_back(val);
    }
    return kPowBase[i];
  }

  // Calculates hash(a || b) from hash(a), hash(b) and length(b).
  static u64 concat(u64 a_hash, u64 b_hash, int b_length) {
    return add(mul(a_hash, pow_base(b_length)), b_hash);
  }
};

// Computes hash for any substring in O(1).
struct SpanHash : public RollingHash {
  std::vector<u64> cum_hash;

  // Constructionn: O(n).
  // All elements must be non-zero. Otherwise we won't be able to distinguish
  // between [1] and [0, 1].
  template<class Sequence>
  explicit SpanHash(const Sequence &s) : cum_hash(s.size() + 1) {
    int i = 0;
    for (const auto &x: s) {
      u64 val = static_cast<u64>(x);
      assert(val != 0);  // Ensure all elements are non-zero!
      cum_hash[i + 1] = add(mul(cum_hash[i], base()), val);
      ++i;
    }
  }

  // Returns the hash value of the substring s[l:r]. O(1).
  u64 get(int l, int r) const {
    // Compute `hash(s[0:r]) - hash(s[0:l]) * B^(r-l) (mod M)`
    return sub(cum_hash.at(r), mul(cum_hash.at(l), pow_base(r - l)));
  }
};

// Binary search over integers
template<class T, class F>
auto bisect(T truthy, T falsy, F pred) -> T {
  static_assert(std::is_integral_v<T>);
  static_assert(std::is_invocable_r_v<bool, F, T>);
  while (std::max(truthy, falsy) - std::min(truthy, falsy) > T(1)) {
    auto mid = (truthy & falsy) + (truthy ^ falsy) / T(2);
    auto ok = pred(mid);
    (ok ? truthy : falsy) = std::move(mid);
  }
  return truthy;
}

template<int alphabet_size = 26, int alphabet_base = 'a', int ROOT_ID = 0>
struct Trie {
  struct Node {
    int c;                                 // character
    std::vector<std::optional<int>> next;  // child node indices
    std::vector<int> entries;  // entry ids stored at the terminal node
    int entry_count;           // how many entries are stored below this node.
    bool ok = false;
    Node(int c_) : c(c_), next(alphabet_size), entry_count(0) {}
  };
  std::vector<Node> nodes;

  Trie() : nodes(1, Node{ROOT_ID}) {}

  void insert(std::string_view entry, int entry_id) {
    int node_id = ROOT_ID;
    for (char ch: entry) {
      ++(nodes[node_id].entry_count);
      int c = int(ch) - alphabet_base;
      auto &next_id = nodes[node_id].next[c];
      if (not next_id.has_value()) {
        next_id = (int) nodes.size();
        nodes.emplace_back(c);
      }
      node_id = next_id.value();
    }
    ++(nodes[node_id].entry_count);
    nodes[node_id].entries.push_back(entry_id);
  }
  void insert(std::string_view entry) {
    insert(entry, nodes[ROOT_ID].entry_count);
  }

  std::optional<const Node *> search(std::string_view entry) const {
    int node_id = ROOT_ID;
    for (char ch: entry) {
      int c = int(ch) - alphabet_base;
      const auto &next_id = nodes[node_id].next[c];
      if (not next_id.has_value()) return nullopt;
      node_id = next_id.value();
    }
    return &nodes[node_id];
  }

  bool contains(std::string_view entry) const {
    auto res = search(entry);
    if (not res.has_value()) return false;
    return not res.value()->entries.empty();
  }

  bool contains_prefix(std::string_view entry) const {
    return search(entry).has_value();
  }
};

Int solve() {
  int n = in, m = in;
  vector<string> S = in(n);
  vector<SpanHash> SH;
  for (const auto &s: S) {
    assert(ssize(s) == m);
    SH.emplace_back(s);
  }
  int count = 0;
  Trie done;
  auto is_subseq = [&](const SpanHash &sh, const SpanHash &th) {
    int plen = bisect(0, m + 1, [&](int i) {
      return sh.get(0, i) == th.get(0, i);
    });
    int slen = bisect(0, m + 1, [&](int i) {
      return sh.get(m - i, m) == th.get(m + 1 - i, m + 1);
    });
    return plen + slen >= m;
  };
  auto is_good = [&](const SpanHash &th) {
    for (int j = 0; j < n; ++j) {
      int plen = bisect(0, m + 1, [&](int i) {
        return SH[j].get(0, i) == th.get(0, i);
      });
      int slen = bisect(0, m + 1, [&](int i) {
        return SH[j].get(m - i, m) == th.get(m + 1 - i, m + 1);
      });
      if (plen + slen >= m) {
        // ok
      } else {
        return false;
      }
    }
    return true;
  };
  auto check = [&](string_view s, const SpanHash &sh) {
    if (done.contains(s)) return;
    done.insert(s);
    if (is_good(sh)) ++count;
  };
  for (int j = 1; j < n; ++j) {
    for (int i = 0; i <= m; ++i) {
      if (SH[j].get(0, i) == SH[0].get(0, i)) {
        string v = S[j].substr(0, i) + S[0][i] + S[j].substr(i);
        SpanHash vh(v);
        if (is_subseq(SH[0], vh)) {
          check(v, vh);
        }
      }
      if (SH[j].get(m - i, m) == SH[0].get(m - i, m)) {
        string v = S[j].substr(0, m - i) + S[0][m - 1 - i] + S[j].substr(m - i);
        SpanHash vh(v);
        if (is_subseq(SH[0], vh)) {
          check(v, vh);
        }
      }
    }
  }
  return count;
}

int main() {
  std::ios::sync_with_stdio(false), cin.tie(nullptr);
  cout << std::fixed << std::setprecision(18);
  const int T = 1;//in;
  REP(t, T) { print(solve()); }
  exit_();
}