結果

問題 No.2606 Mirror Relay
コンテスト
ユーザー risujiroh
提出日時 2024-01-12 22:41:54
言語 C++23
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 107 ms / 2,000 ms
コード長 7,195 bytes
コンパイル時間 4,722 ms
コンパイル使用メモリ 297,876 KB
実行使用メモリ 28,796 KB
最終ジャッジ日時 2024-09-27 23:25:30
合計ジャッジ時間 8,817 ms
ジャッジサーバーID
（参考情報） 		judge2 / judge3
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 * 4
other AC * 69
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 # 

#if __INCLUDE_LEVEL__ == 0

#include __BASE_FILE__

namespace {

int op(int x, int y) { return std::min(x, y); }
int e() { return inf(); }

void solve() {
  std::string s;
  scan(s);
  const int n = len(s);

  const auto sa = atcoder::suffix_array(s);
  const auto la = atcoder::lcp_array(s, sa);
  const atcoder::segtree<int, op, e> seg(la);

  std::vector<int> isa(n);
  for (const int k : rep(n)) {
    const int i = sa[k];
    isa[i] = k;
  }

  std::vector<i64> f(n + 1);

  const auto ls = nyaan::enumerate_leftmost_palindromes(s);
  std::vector<std::set<int>> seen(n);
  for (const int r : rep1(n)) {
    const int l = ls[r - 1];
    const int k = isa[l];
    const int rk = seg.max_right(k, r - l <= _1) + 1;
    const int lk = seg.min_left(k, r - l <= _1);
    if (seen[lk].contains(r - l)) {
      continue;
    }
    seen[lk].insert(r - l);
    f[lk] += i64(r - l) * (rk - lk);
    f[rk] -= i64(r - l) * (rk - lk);
  }

  std::partial_sum(f.begin(), f.end(), f.begin());

  print(ranges::max(f));
}

}  // namespace

int main() {
  std::ios::sync_with_stdio(false);
  std::cin.tie(nullptr);

  solve();
}

#else  // __INCLUDE_LEVEL__

#include <bits/stdc++.h>

#include <atcoder/segtree>
#include <atcoder/string>

// https://nyaannyaan.github.io/library/string/manacher.hpp
namespace nyaan {

using namespace std;

template <typename Container>
vector<int> manacher(const Container& S) {
  vector<int> res(S.size());
  int i = 0, j = 0;
  while (i < int(S.size())) {
    while (i - j >= 0 and i + j < int(S.size()) and S[i - j] == S[i + j]) j++;
    res[i] = j;
    int k = 1;
    while (i - k >= 0 and i + k < int(S.size()) and k + res[i - k] < j)
      res[i + k] = res[i - k], k++;
    i += k, j -= k;
  }
  return res;
}

template <typename Container>
vector<pair<int, int>> enumerate_palindromes(const Container& vec) {
  using T = typename Container::value_type;
  vector<T> v;
  const int N = vec.size();
  for (int i = 0; i < N - 1; i++) {
    v.push_back(vec[i]);
    v.push_back(-1);
  }
  v.push_back(vec.back());
  const auto man = manacher(v);
  vector<pair<int, int>> ret;
  for (int i = 0; i < N * 2 - 1; i++) {
    if (i & 1) {
      int w = man[i] / 2;
      ret.emplace_back((i + 1) / 2 - w, (i + 1) / 2 + w);
    } else {
      int w = (man[i] - 1) / 2;
      ret.emplace_back(i / 2 - w, i / 2 + w + 1);
    }
  }
  return ret;
}

template <typename Container>
vector<int> enumerate_leftmost_palindromes(const Container& vec) {
  vector<int> v(vec.size(), 1);
  for (auto& [l, r] : enumerate_palindromes(vec)) {
    v[r - 1] = max(v[r - 1], r - l);
  }
  for (int i = (int)vec.size() - 2; i >= 0; i--) v[i] = max(v[i], v[i + 1] - 2);
  vector<int> ret(vec.size());
  for (int i = 0; i < (int)vec.size(); i++) ret[i] = i + 1 - v[i];
  return ret;
}

}  // namespace nyaan

template <class T, class U = T>
bool chmin(T& x, U&& y) {
  return y < x && (x = std::forward<U>(y), true);
}

template <class T, class U = T>
bool chmax(T& x, U&& y) {
  return x < y && (x = std::forward<U>(y), true);
}

template <std::signed_integral T = int>
T inf() {
  T ret;
  std::memset(&ret, 0x3f, sizeof(ret));
  return ret;
}

template <std::floating_point T>
T inf() {
  return std::numeric_limits<T>::infinity();
}

template <class T>
concept Range = std::ranges::range<T> && !std::convertible_to<T, std::string_view>;

template <class T>
concept TupleLike = std::__is_tuple_like<T>::value && !Range<T>;

namespace std {

istream& operator>>(istream& is, Range auto&& r) {
  for (auto&& e : r) {
    is >> e;
  }
  return is;
}

istream& operator>>(istream& is, TupleLike auto&& t) {
  return apply([&](auto&... xs) -> istream& { return (is >> ... >> xs); }, t);
}

ostream& operator<<(ostream& os, Range auto&& r) {
  string_view sep = "";
  for (auto&& e : r) {
    os << exchange(sep, " ") << e;
  }
  return os;
}

ostream& operator<<(ostream& os, TupleLike auto&& t) {
  const auto f = [&](auto&... xs) -> ostream& {
    [[maybe_unused]] string_view sep = "";
    ((os << exchange(sep, " ") << xs), ...);
    return os;
  };
  return apply(f, t);
}

#define DEF_INC_OR_DEC(op) \
  auto& operator op(Range auto&& r) { \
    for (auto&& e : r) { \
      op e; \
    } \
    return r; \
  } \
  auto& operator op(TupleLike auto&& t) { \
    apply([](auto&... xs) { (op xs, ...); }, t); \
    return t; \
  }

DEF_INC_OR_DEC(++)
DEF_INC_OR_DEC(--)

#undef DEF_INC_OR_DEC

}  // namespace std

void scan(auto&&... xs) { std::cin >> std::tie(xs...); }
void print(auto&&... xs) { std::cout << std::tie(xs...) << '\n'; }

#define FWD(...) static_cast<decltype(__VA_ARGS__)&&>(__VA_ARGS__)

template <class F>
class fix {
 public:
  explicit fix(F f) : f_(std::move(f)) {}

  decltype(auto) operator()(auto&&... xs) const { return f_(std::ref(*this), FWD(xs)...); }

 private:
  F f_;
};

template <class T>
concept LambdaExpr = std::is_placeholder_v<std::remove_cvref_t<T>> != 0 ||
                     std::is_bind_expression_v<std::remove_cvref_t<T>>;

auto operator++(LambdaExpr auto&& x, int) {
  return std::bind([](auto&& x) -> decltype(auto) { return FWD(x)++; }, FWD(x));
}

auto operator--(LambdaExpr auto&& x, int) {
  return std::bind([](auto&& x) -> decltype(auto) { return FWD(x)--; }, FWD(x));
}

#define DEF_UNARY_OP(op) \
  auto operator op(LambdaExpr auto&& x) { \
    return std::bind([](auto&& x) -> decltype(auto) { return op FWD(x); }, FWD(x)); \
  }

DEF_UNARY_OP(++)
DEF_UNARY_OP(--)
DEF_UNARY_OP(+)
DEF_UNARY_OP(-)
DEF_UNARY_OP(~)
DEF_UNARY_OP(!)
DEF_UNARY_OP(*)
DEF_UNARY_OP(&)

#undef DEF_UNARY_OP

#define DEF_BINARY_OP(op) \
  template <class T1, class T2> \
    requires LambdaExpr<T1> || LambdaExpr<T2> \
  auto operator op(T1&& x, T2&& y) { \
    return std::bind([](auto&& x, auto&& y) -> decltype(auto) { return FWD(x) op FWD(y); }, \
                     FWD(x), FWD(y)); \
  }

DEF_BINARY_OP(+=)
DEF_BINARY_OP(-=)
DEF_BINARY_OP(*=)
DEF_BINARY_OP(/=)
DEF_BINARY_OP(%=)
DEF_BINARY_OP(^=)
DEF_BINARY_OP(&=)
DEF_BINARY_OP(|=)
DEF_BINARY_OP(<<=)
DEF_BINARY_OP(>>=)
DEF_BINARY_OP(+)
DEF_BINARY_OP(-)
DEF_BINARY_OP(*)
DEF_BINARY_OP(/)
DEF_BINARY_OP(%)
DEF_BINARY_OP(^)
DEF_BINARY_OP(&)
DEF_BINARY_OP(|)
DEF_BINARY_OP(<<)
DEF_BINARY_OP(>>)
DEF_BINARY_OP(==)
DEF_BINARY_OP(!=)
DEF_BINARY_OP(<)
DEF_BINARY_OP(>)
DEF_BINARY_OP(<=)
DEF_BINARY_OP(>=)
DEF_BINARY_OP(&&)
DEF_BINARY_OP(||)

#undef DEF_BINARY_OP

template <class T1, class T2>
  requires LambdaExpr<T1> || LambdaExpr<T2>
auto at(T1&& x, T2&& y) {
  return std::bind([](auto&& x, auto&& y) -> decltype(auto) { return FWD(x)[FWD(y)]; }, FWD(x),
                   FWD(y));
}

template <int I>
auto get(LambdaExpr auto&& x) {
  return std::bind([](auto&& x) -> decltype(auto) { return std::get<I>(FWD(x)); }, FWD(x));
}

inline auto rep(int l, int r) { return std::views::iota(std::min(l, r), r); }
inline auto rep(int n) { return rep(0, n); }
inline auto rep1(int l, int r) { return rep(l, r + 1); }
inline auto rep1(int n) { return rep(1, n + 1); }

using namespace std::literals;
using namespace std::placeholders;

namespace ranges = std::ranges;
namespace views = std::views;

using i64 = std::int64_t;

#define len(...) static_cast<int>(ranges::size(__VA_ARGS__))

#endif  // __INCLUDE_LEVEL__
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