tests/string/palindrome.test.cpp

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Last update: 2025-09-23 20:38:32+09:00
Problem: https://judge.yosupo.jp/problem/enumerate_palindromes

Depends on

Code

#define PROBLEM "https://judge.yosupo.jp/problem/enumerate_palindromes"

#include <bits/stdc++.h>
#include "ugilib/base/constants.hpp"
#include "ugilib/base/definitions.hpp"
#include "ugilib/awesome_external_lib/rainbou-kpr/rolling-hash.hpp"
#include "ugilib/string/palindrome.hpp"
// #include "atcoder/segtree.hpp"

using namespace std;

// debug settings
// #define DEBUG
#ifdef DEBUG
// debug input
string _INPUT = R"(
5
1 2 3 4 5
)";
auto _cin = stringstream(_INPUT.substr(1)); // remove '\n' at _INPUT[0]
#else
// standard input
auto& _cin = cin;
#endif

// speed up
#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")

// reader
struct rd {
    // T
    template<typename T> static T i() { T x; _cin >> x; return x; }  // T item
    // vector<T>
    template<typename T> static vector<T> v(int n) {vector<T> v(n); rep(i, n) _cin >> v[i]; return v;}  // vector<T>
    // vector<pair<T, T>>
    template<typename T> static vector<pair<T, T>> vp(int n) {vector<pair<T, T>> v(n); rep(i, n) _cin >> v[i].first >> v[i].second; return v;}  // vector<pair<T, T>>
    // tuple
    template<typename... Args> static tuple<Args...> t() {
        tuple<Args...> values;
        apply([](auto&... args) { ((_cin >> args), ...); }, values);
        return values;
    }
};

// debug print utility
namespace deb {
    #include <cxxabi.h>
    // demangle type name
    string demangle(const char* name) {
        int status = -4;
        unique_ptr<char, void(*)(void*)> res{
            abi::__cxa_demangle(name, NULL, NULL, &status),
            free
        };
        return (status == 0) ? string(res.get()) : name ;
    }
    // meta functions for type traits
    template<typename T>
    constexpr bool isArithmeticContainer() { return is_arithmetic<typename T::value_type>::value; }
    // for SFINAE
    template<typename T, typename = void> struct has_key_and_mapped_type : false_type {};
    template<typename T> struct has_key_and_mapped_type<T, void_t<typename T::key_type, typename T::mapped_type>> : true_type {};
    // for map or unordered_map
    template<typename T>
    constexpr bool isMapLike() { return has_key_and_mapped_type<T>::value; }

    // for values
    template<typename T, typename enable_if<is_arithmetic<T>::value, nullptr_t>::type = nullptr>
    void p(const T& x) { cout << x << " "; }
    // for pairs
    template <typename T, typename S>
    void p(const pair<T, S>& _p){ p(_p.first); p(_p.second); cout << endl; }
    // for string
    void p(const string& s) { cout << s << endl; }
    // for containers
    template<typename T,  typename enable_if<!is_arithmetic<T>::value, nullptr_t>::type = nullptr>
    void p(const T& container) {
        // map and unordered_map
        if constexpr (isMapLike<T>()) {
            cout << demangle(typeid(T).name()) << ":" << endl;
            for (const auto& kv : container) {
                cout << "[" << kv.first << "] => ";
                p(kv.second);
                if constexpr (is_arithmetic_v<typename T::mapped_type>) cout << endl;
            }
        // vector or set or others
        } else {
            if constexpr (!isArithmeticContainer<T>()) cout << demangle(typeid(T).name()) << ":" << endl;
            for (auto it = begin(container); it != end(container); ++it) {
                p(*it);
            }
            if constexpr (isArithmeticContainer<T>()) cout << endl;
        }
    }
};  // namespace deb

int main() {
    auto& cin = _cin;
    // speed up io
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    // code
    string s = rd::i<string>();

    ugilib::rainbou_kpr::RollingHash rh;
    vector<unsigned long long> forward_hash = rh.build(s.begin(), s.end());
    vector<unsigned long long> backward_hash = rh.build(s.rbegin(), s.rend());

    for (int i = 0; i < 2*s.size() - 1; i++) {
        int center = i / 2;
        int is_range_odd = i % 2 == 0;  // 中心が特定の値の時はそれをスキップする

        int ok = 0;
        int ng = s.size();
        while (ok + 1 < ng) {
            int mid = (ok + ng) / 2;

            int left = center - (mid - 1 + is_range_odd);
            int right = center + mid + 1;

            if (ugilib::is_palindrome_lr(rh, forward_hash, backward_hash, left, right)) {
                ok = mid;
            } else {
                ng = mid;
            }
        }

        int length = ok * 2 + 1 * is_range_odd;
        cout << length << " \n"[i+1 == 2*s.size() - 1];
    }
}

// セグ木に載せるとO(N log^2 N)でクエリを処理できる
// でもちゃんとやればO(N log N)でできる
/**
ugilib::rainbou_kpr::RollingHash rh;
using S = ugilib::rainbou_kpr::RHString;
S op(S a, S b) {
    return a + b;
}
S e() {
    return S(rh);
}

int main() {
    auto& cin = _cin;
    // speed up io
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    // code
    string s = rd::i<string>();
    vector<S> initializer;
    for (char c : s) {
        initializer.emplace_back(rh, c);
    }
    atcoder::segtree<S, op, e> sgt(initializer);

    ll N = s.size();
    for (int i = 0; i < 2*N - 1; i++) {
        bool is_interval = (i % 2 == 1);

        int ok = 0;
        int ng = (int)N;
        while (ok + 1 < ng) {
            int mid = (ok + ng) / 2;

            int left = i/2 - mid + is_interval;
            int right = i/2 + mid + 1;
            if (left < 0 || N < right) {
                ng = mid;
            } else if (sgt.prod(left, right).is_palindrome()) {
                ok = mid;
            } else {
                ng = mid;
            }
        }
        int length = ok * 2 + (1 ^ is_interval);
        cout << length << " \n"[i+1 == 2*N - 1];
        // cout << "i: " << i << ", length: " << length << endl;
        // cout << "ok: " << ok << ", ng: " << ng << endl;
        // cout << s.substr(i/2 - ok + is_interval, length) << endl;
    }

    return 0;
}
*/

#line 1 "tests/string/palindrome.test.cpp"
#define PROBLEM "https://judge.yosupo.jp/problem/enumerate_palindromes"

#include <bits/stdc++.h>
#line 3 "ugilib/base/definitions.hpp"

// old (compat)
using ll = long long;
using ull = unsigned long long;
using ld = long double;

// new
using u8 = uint8_t;
using u16 = uint16_t;
using u32 = uint32_t;
using u64 = uint64_t;
using u128 = __uint128_t;
using i8 = int8_t;
using i16 = int16_t;
using i32 = int32_t;
using i64 = int64_t;
using i128 = __int128_t;
using f32 = float;
using f64 = double;
using f128 = long double;

#define rep(i, n) for(size_t i = 0; i < n; i++)  // rep macro
#define all(v) begin(v), end(v)  // all iterator
#line 4 "ugilib/base/constants.hpp"

namespace ugilib::constants {
    template<typename T>
    inline constexpr T INF = std::numeric_limits<T>::max() / 2;
} // namespace ugilib::constants

const ll INF = ugilib::constants::INF<ll>;
#line 2 "ugilib/awesome_external_lib/rainbou-kpr/rolling-hash.hpp"

/**
 * @file rolling-hash.hpp
 * @brief ローリングハッシュを扱うヘッダ
 * @note https://github.com/rainbou-kpr/libraryからのコピーです
 */

#line 13 "ugilib/awesome_external_lib/rainbou-kpr/rolling-hash.hpp"
#include <string_view>
#include <type_traits>

#line 2 "ugilib/awesome_external_lib/rainbou-kpr/traits.hpp"

/**
 * @file traits.hpp
 * @brief 型特性を扱うヘッダ
 * @note https://github.com/rainbou-kpr/libraryからのコピーです
 */

#line 12 "ugilib/awesome_external_lib/rainbou-kpr/traits.hpp"

namespace ugilib::rainbou_kpr {
    namespace detail {
    using std::begin, std::end;

    template <class T, class = void>
    struct is_range_impl : std::false_type {};
    template <class T>
    struct is_range_impl<T, std::void_t<decltype(begin(std::declval<T&>()), end(std::declval<T&>()))>> : std::true_type {};
    }  // namespace detail

    template <class T>
    struct is_range : detail::is_range_impl<T>::type {};
    template <class T>
    inline constexpr bool is_range_v = is_range<T>::value;
}  // namespace ugilib::rainbou_kpr
#line 17 "ugilib/awesome_external_lib/rainbou-kpr/rolling-hash.hpp"

namespace ugilib::rainbou_kpr {
    struct RHString;

    /**
     * @brief ローリングハッシュ
     *
     * ビット演算に寄る高速化のためハッシュはMOD = 2^61-1で計算される
     *
     * 10^8個くらいなら99%の確率で衝突する組が存在しない
     */
    class RollingHash {
        constexpr static unsigned long long MASK30 = (1ULL << 30) - 1;
        constexpr static unsigned long long MASK31 = (1ULL << 31) - 1;
        constexpr static unsigned long long MOD = (1ULL << 61) - 1;

        // a < MOD, b < MOD必須
        constexpr static unsigned long long add(unsigned long long a, unsigned long long b) {
            if((a += b) >= MOD) a -= MOD;
            return a;
        }

        // a < MOD, b < MOD必須
        constexpr static unsigned long long mul(unsigned long long a, unsigned long long b) {
            __uint128_t c = static_cast<__uint128_t>(a) * b;
            return add(static_cast<unsigned long long>(c >> 61), static_cast<unsigned long long>(c & MOD));
        }

        void expand(int n) {
            while(static_cast<int>(power.size()) <= n) power.push_back(mul(power.back(), base));
        }

    public:
        unsigned int base; //!< ハッシュの基数
        std::vector<unsigned long long> power; //!< baseの累乗

        /**
         * @brief コンストラクタ
         *
         * @param base ハッシュの基数 省略するとランダム
         */
        RollingHash(unsigned int base = 0) : base(base) {
            if(base == 0) {
                std::mt19937 mt(std::random_device{}());
                this->base = std::uniform_int_distribution<unsigned int>(129, ~0U)(mt);
            }
            power = {1};
        }

        /**
         * @brief 配列/文字列のイテレータ間のハッシュの計算(O(N))
         *
         * @tparam It イテレータ
         * @param first 配列の開始イテレータ
         * @param last 配列の終了イテレータ
         * @return std::vector<unsigned long long> 先頭から各要素数分のハッシュ
         */
        template <typename It>
        std::vector<unsigned long long> build(It first, It last) {
            std::vector<unsigned long long> res;
            if constexpr (std::is_convertible_v<typename std::iterator_traits<It>::iterator_category, std::random_access_iterator_tag>) {
                res.reserve(last - first + 1);
            }
            res.push_back(0);
            for(; first != last; ++first) {
                res.push_back(add(mul(res.back(), base), *first));
            }
            return res;
        }

        /**
         * @brief 配列/文字列全体のハッシュの計算(O(N))
         *
         * @param s 配列/文字列
         * @return std::vector<unsigned long long> 先頭から各文字数分のハッシュ
         */
        template <typename R>
        std::vector<unsigned long long> build(R&& s) {
            using std::begin, std::end;
            return build(begin(s), end(s));
        }

        /**
         * @brief [l,r)のハッシュの計算(O(1))
         *
         * @param hash 先頭からのハッシュ
         * @param l 区間の左端
         * @param r 区間の右端
         * @return unsigned long long [l,r)のハッシュ
         */
        unsigned long long query(const std::vector<unsigned long long>& hash, int l, int r) {
            expand(r - l);
            return add(hash[r], MOD - mul(hash[l], power[r-l]));
        }

        friend RHString;
    };

    /**
     * @brief ローリングハッシュによって管理される文字列型
     */
    struct RHString {
        RollingHash& rh;
        size_t sz;
        unsigned long long hash1;  //!< 正順
        unsigned long long hash2;  //!< 逆順
        /**
         * @brief コンストラクタ
         * 予めRollingHashをインスタンス化しておく必要がある
         */
        RHString(RollingHash& rh) : rh(rh), sz(0), hash1(0), hash2(0) {}
        RHString(RollingHash& rh, size_t sz, unsigned long long hash1, unsigned long long hash2) : rh(rh), sz(sz), hash1(hash1), hash2(hash2) {}
        RHString(const RHString& o) : rh(o.rh), sz(o.sz), hash1(o.hash1), hash2(o.hash2) {}
        /**
         * @brief vectorなどで初期化する
         */
        template <class R, std::enable_if_t<is_range_v<R> && !std::is_convertible_v<R, std::string_view>, std::nullptr_t> = nullptr>
        RHString(RollingHash& rh, R&& v) : rh(rh) {
            using std::begin, std::end, std::rbegin, std::rend;
            sz = std::distance(begin(v), end(v));
            hash1 = rh.build(begin(v), end(v)).back();
            hash2 = rh.build(rbegin(v), rend(v)).back();
        }
        /**
         * @brief charやunsigned long longなどで初期化する
         */
        template <class T, std::enable_if_t<std::is_convertible_v<T, unsigned long long> && !std::is_convertible_v<T, std::string_view>, std::nullptr_t> = nullptr>
        RHString(RollingHash& rh, T&& x) : rh(rh) {
            sz = 1;
            hash1 = x;
            hash2 = x;
        }
        /**
         * @brief 文字列(string, const char*, string_view)で初期化する
         */
        RHString(RollingHash& rh, std::string_view s) : rh(rh) {
            sz = std::distance(s.begin(), s.end());
            hash1 = rh.build(s.begin(), s.end()).back();
            hash2 = rh.build(s.rbegin(), s.rend()).back();
        }

        /**
         * @brief 回文か否か
         */
        bool is_palindrome() const {
            return hash1 == hash2;
        }
        size_t size() const {
            return sz;
        }
        void clear() {
            sz = 0;
            hash1 = 0;
            hash2 = 0;
        }
        bool empty() const {
            return sz == 0;
        }
        RHString& operator+=(const RHString& o) {
            assert(&rh == &o.rh);
            rh.expand(sz);
            rh.expand(o.sz);
            hash1 = rh.add(rh.mul(hash1, rh.power[o.sz]), o.hash1);
            hash2 = rh.add(hash2, rh.mul(o.hash2, rh.power[sz]));
            sz += o.sz;
            return *this;
        }
        /**
         * @brief 再代入する
         * RollingHashは同じものである必要がある
         */
        void assign(const RHString& o) {
            assert(&rh == &o.rh);
            sz = o.sz;
            hash1 = o.hash1;
            hash2 = o.hash2;
        }
        /**
         * @brief vectorなどを再代入する
         */
        template <class R, std::enable_if_t<is_range_v<R> && !std::is_convertible_v<R, std::string_view>, std::nullptr_t> = nullptr>
        void assign(R&& v) {
            using std::begin, std::end, std::rbegin, std::rend;
            sz = std::distance(begin(v), end(v));
            hash1 = rh.build(begin(v), end(v)).back();
            hash2 = rh.build(rbegin(v), rend(v)).back();
        }
        /**
         * @brief charやunsigned long longなどを再代入する
         */
        template <class T, std::enable_if_t<std::is_convertible_v<T, unsigned long long> && !std::is_convertible_v<T, std::string_view>, std::nullptr_t> = nullptr>
        void assign(T&& x) {
            sz = 1;
            hash1 = x;
            hash2 = x;
        }
        /**
         * @brief 文字列(string, const char*, string_view)を再代入する
         */
        void assign(std::string_view s) {
            sz = std::distance(s.begin(), s.end());
            hash1 = rh.build(s.begin(), s.end()).back();
            hash2 = rh.build(s.rbegin(), s.rend()).back();
        }
        /**
         * @brief 再代入する
         * RollingHashは同じものである必要がある
         */
        RHString& operator=(const RHString& o) {
            assign(o);
            return *this;
        }
        /**
         * @brief vectorなどを再代入する
         */
        template <class R, std::enable_if_t<is_range_v<R> && !std::is_convertible_v<R, std::string_view>, std::nullptr_t> = nullptr>
        RHString& operator=(R&& v) {
            assign(v);
            return *this;
        }
        /**
         * @brief charやunsigned long longなどを再代入する
         */
        template <class T, std::enable_if_t<std::is_convertible_v<T, unsigned long long> && !std::is_convertible_v<T, std::string_view>, std::nullptr_t> = nullptr>
        RHString& operator=(T&& x) {
            assign(x);
            return *this;
        }
        /**
         * @brief 文字列(string, const char*, string_view)を再代入する
         */
        RHString& operator=(std::string_view s) {
            assign(s);
            return *this;
        }
        friend RHString operator+(const RHString& t1, const RHString& t2) {
            RHString ret = t1;
            ret += t2;
            return ret;
        }
        friend bool operator==(const RHString& t1, const RHString& t2) {
            assert(&t1.rh == &t2.rh);
            return t1.sz == t2.sz && t1.hash1 == t2.hash1 && t1.hash2 == t2.hash2;
        }
        friend bool operator!=(const RHString& t1, const RHString& t2) { return !(t1 == t2); }
    };
}  // namespace ugilib::rainbou_kpr
#line 2 "ugilib/string/palindrome.hpp"

#line 5 "ugilib/string/palindrome.hpp"

namespace ugilib {
    using namespace std;
    /**
     * @brief 列の[l, r)が回文かどうかを判定する
     * @param rh ハッシュ生成に使ったRollingHash
     * @param forward_hash 順方向のハッシュ
     * @param backward_hash 逆方向のハッシュ
     * @param l 左端
     * @param r 右端
     * @return 回文ならtrue. 範囲が不正な場合や回文ではない場合にfalseを返す
     * @note O(1)
    */
    bool is_palindrome_lr(ugilib::rainbou_kpr::RollingHash &rh, const vector<unsigned long long> &forward_hash, const vector<unsigned long long> &backward_hash, const int l, const int r) {
        const int s_size = forward_hash.size() - 1;

        if (l < 0 || s_size < r) return false;  // 0-indexed, [l, r)
        if (r <= l) return false;

        // 範囲が奇数の場合は中央をスキップ
        bool is_range_odd = (r - l) % 2 == 1;

        // 範囲を計算
        int mid = (l + r) / 2;
        pair<int, int> left = {l, mid};  // [l, mid)
        pair<int, int> right = {mid + is_range_odd, r};  // [mid, r)

        // ハッシュ値を取得
        unsigned long long left_hash = rh.query(forward_hash, left.first, left.second);
        unsigned long long right_hash = rh.query(backward_hash, s_size - right.second, s_size - right.first);

        return left_hash == right_hash;
    }
}
#line 8 "tests/string/palindrome.test.cpp"
// #include "atcoder/segtree.hpp"

using namespace std;

// debug settings
// #define DEBUG
#ifdef DEBUG
// debug input
string _INPUT = R"(
5
1 2 3 4 5
)";
auto _cin = stringstream(_INPUT.substr(1)); // remove '\n' at _INPUT[0]
#else
// standard input
auto& _cin = cin;
#endif

// speed up
#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")

// reader
struct rd {
    // T
    template<typename T> static T i() { T x; _cin >> x; return x; }  // T item
    // vector<T>
    template<typename T> static vector<T> v(int n) {vector<T> v(n); rep(i, n) _cin >> v[i]; return v;}  // vector<T>
    // vector<pair<T, T>>
    template<typename T> static vector<pair<T, T>> vp(int n) {vector<pair<T, T>> v(n); rep(i, n) _cin >> v[i].first >> v[i].second; return v;}  // vector<pair<T, T>>
    // tuple
    template<typename... Args> static tuple<Args...> t() {
        tuple<Args...> values;
        apply([](auto&... args) { ((_cin >> args), ...); }, values);
        return values;
    }
};

// debug print utility
namespace deb {
    #include <cxxabi.h>
    // demangle type name
    string demangle(const char* name) {
        int status = -4;
        unique_ptr<char, void(*)(void*)> res{
            abi::__cxa_demangle(name, NULL, NULL, &status),
            free
        };
        return (status == 0) ? string(res.get()) : name ;
    }
    // meta functions for type traits
    template<typename T>
    constexpr bool isArithmeticContainer() { return is_arithmetic<typename T::value_type>::value; }
    // for SFINAE
    template<typename T, typename = void> struct has_key_and_mapped_type : false_type {};
    template<typename T> struct has_key_and_mapped_type<T, void_t<typename T::key_type, typename T::mapped_type>> : true_type {};
    // for map or unordered_map
    template<typename T>
    constexpr bool isMapLike() { return has_key_and_mapped_type<T>::value; }

    // for values
    template<typename T, typename enable_if<is_arithmetic<T>::value, nullptr_t>::type = nullptr>
    void p(const T& x) { cout << x << " "; }
    // for pairs
    template <typename T, typename S>
    void p(const pair<T, S>& _p){ p(_p.first); p(_p.second); cout << endl; }
    // for string
    void p(const string& s) { cout << s << endl; }
    // for containers
    template<typename T,  typename enable_if<!is_arithmetic<T>::value, nullptr_t>::type = nullptr>
    void p(const T& container) {
        // map and unordered_map
        if constexpr (isMapLike<T>()) {
            cout << demangle(typeid(T).name()) << ":" << endl;
            for (const auto& kv : container) {
                cout << "[" << kv.first << "] => ";
                p(kv.second);
                if constexpr (is_arithmetic_v<typename T::mapped_type>) cout << endl;
            }
        // vector or set or others
        } else {
            if constexpr (!isArithmeticContainer<T>()) cout << demangle(typeid(T).name()) << ":" << endl;
            for (auto it = begin(container); it != end(container); ++it) {
                p(*it);
            }
            if constexpr (isArithmeticContainer<T>()) cout << endl;
        }
    }
};  // namespace deb

int main() {
    auto& cin = _cin;
    // speed up io
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    // code
    string s = rd::i<string>();

    ugilib::rainbou_kpr::RollingHash rh;
    vector<unsigned long long> forward_hash = rh.build(s.begin(), s.end());
    vector<unsigned long long> backward_hash = rh.build(s.rbegin(), s.rend());

    for (int i = 0; i < 2*s.size() - 1; i++) {
        int center = i / 2;
        int is_range_odd = i % 2 == 0;  // 中心が特定の値の時はそれをスキップする

        int ok = 0;
        int ng = s.size();
        while (ok + 1 < ng) {
            int mid = (ok + ng) / 2;

            int left = center - (mid - 1 + is_range_odd);
            int right = center + mid + 1;

            if (ugilib::is_palindrome_lr(rh, forward_hash, backward_hash, left, right)) {
                ok = mid;
            } else {
                ng = mid;
            }
        }

        int length = ok * 2 + 1 * is_range_odd;
        cout << length << " \n"[i+1 == 2*s.size() - 1];
    }
}

// セグ木に載せるとO(N log^2 N)でクエリを処理できる
// でもちゃんとやればO(N log N)でできる
/**
ugilib::rainbou_kpr::RollingHash rh;
using S = ugilib::rainbou_kpr::RHString;
S op(S a, S b) {
    return a + b;
}
S e() {
    return S(rh);
}

int main() {
    auto& cin = _cin;
    // speed up io
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    // code
    string s = rd::i<string>();
    vector<S> initializer;
    for (char c : s) {
        initializer.emplace_back(rh, c);
    }
    atcoder::segtree<S, op, e> sgt(initializer);

    ll N = s.size();
    for (int i = 0; i < 2*N - 1; i++) {
        bool is_interval = (i % 2 == 1);

        int ok = 0;
        int ng = (int)N;
        while (ok + 1 < ng) {
            int mid = (ok + ng) / 2;

            int left = i/2 - mid + is_interval;
            int right = i/2 + mid + 1;
            if (left < 0 || N < right) {
                ng = mid;
            } else if (sgt.prod(left, right).is_palindrome()) {
                ok = mid;
            } else {
                ng = mid;
            }
        }
        int length = ok * 2 + (1 ^ is_interval);
        cout << length << " \n"[i+1 == 2*N - 1];
        // cout << "i: " << i << ", length: " << length << endl;
        // cout << "ok: " << ok << ", ng: " << ng << endl;
        // cout << s.substr(i/2 - ok + is_interval, length) << endl;
    }

    return 0;
}
*/