算法模板目录 ：个人算法模板

template<class T>
constexpr T power(T a, LL b) {
    T res = 1;
    for (; b; b /= 2, a *= a) {
        if (b % 2) {
            res *= a;
        }
    }
    return res;
}
template<int P>
struct MInt {
    int x;
    constexpr MInt() : x{} {}
    constexpr MInt(LL x) : x{norm(x % getMod())} {}

    static int Mod;
    constexpr static int getMod() {
        if (P > 0) {
            return P;
        } else {
            return Mod;
        }
    }
    constexpr static void setMod(int Mod_) {
        Mod = Mod_;
    }
    constexpr int norm(int x) const {
        if (x < 0) {
            x += getMod();
        }
        if (x >= getMod()) {
            x -= getMod();
        }
        return x;
    }
    constexpr int val() const {
        return x;
    }
    explicit constexpr operator int() const {
        return x;
    }
    constexpr MInt operator-() const {
        MInt res;
        res.x = norm(getMod() - x);
        return res;
    }
    constexpr MInt inv() const {
        assert(x != 0);
        return power(*this, getMod() - 2);
    }
    constexpr MInt &operator*=(MInt rhs) & {
        x = 1LL * x * rhs.x % getMod();
        return *this;
    }
    constexpr MInt &operator+=(MInt rhs) & {
        x = norm(x + rhs.x);
        return *this;
    }
    constexpr MInt &operator-=(MInt rhs) & {
        x = norm(x - rhs.x);
        return *this;
    }
    constexpr MInt &operator/=(MInt rhs) & {
        return *this *= rhs.inv();
    }
    friend constexpr MInt operator*(MInt lhs, MInt rhs) {
        MInt res = lhs;
        res *= rhs;
        return res;
    }
    friend constexpr MInt operator+(MInt lhs, MInt rhs) {
        MInt res = lhs;
        res += rhs;
        return res;
    }
    friend constexpr MInt operator-(MInt lhs, MInt rhs) {
        MInt res = lhs;
        res -= rhs;
        return res;
    }
    friend constexpr MInt operator/(MInt lhs, MInt rhs) {
        MInt res = lhs;
        res /= rhs;
        return res;
    }
    friend constexpr std::istream &operator>>(std::istream &is, MInt &a) {
        LL v;
        is >> v;
        a = MInt(v);
        return is;
    }
    friend constexpr std::ostream &operator<<(std::ostream &os, const MInt &a) {
        return os << a.val();
    }
    friend constexpr bool operator==(MInt lhs, MInt rhs) {
        return lhs.val() == rhs.val();
    }
    friend constexpr bool operator!=(MInt lhs, MInt rhs) {
        return lhs.val() != rhs.val();
    }
};

template<>
int MInt<0>::Mod = 998244353;

template<int V, int P>
constexpr MInt<P> CInv = MInt<P>(V).inv();

constexpr int P = 1000000007;
using Z = MInt<P>;

template <typename T, const int P>
struct single_hash {
    int n;
    std::vector<T> h, hi, p;
    single_hash(string s) : n(s.size() - 1), h(n + 1), hi(n + 2), p(n + 1) {
        p[0] = 1;
        for (int i = 1; i <= n; i++) {
            p[i] = p[i - 1] * P;
            h[i] = h[i - 1] * P + s[i];
        }
        for (int i = n; i >= 1; i--) {
            hi[i] = hi[i + 1] * P + s[i];
        }
    }
    T get(int l, int r) {
        return h[r] - h[l - 1] * p[r - l + 1];
    }
    T geti(int l, int r) {
        return hi[l] - hi[r + 1] * p[r - l + 1];
    }
    bool ispalindrome(int l, int r) {
        return get(l, r) == geti(l, r);
    }
    bool same(int l1, int r1, int l2, int r2) {
        return get(l1, r1) == get(l2, r2);
    }
    T MergeFF(int l1, int r1, int l2, int r2) { // Forward and Forward
        return get(l1, r1) * p[r2 - l2 + 1] + get(l2, r2);
    }
    T MergeFR(int l1, int r1, int l2, int r2) { // Forward and reverse
        return get(l1, r1) * p[r2 - l2 + 1] + geti(l2, r2);
    }
    T MergeRF(int l1, int r1, int l2, int r2) { // reverse and Forward
        return geti(l1, r1) * p[r2 - l2 + 1] + get(l2, r2);
    }
    T MergeRR(int l1, int r1, int l2, int r2) { // reverse and reverse
        return geti(l1, r1) * p[r2 - l2 + 1] + geti(l2, r2);
    }
};
using SingleHash1 = single_hash<MInt<P>, 131>;
using SingleHash2 = single_hash<MInt<0>, 13331>;

struct DoubleHash : SingleHash1, SingleHash2 {
    using SingleHash1::single_hash;
    using SingleHash2::single_hash;

    DoubleHash(string s) : SingleHash1::single_hash(s), SingleHash2::single_hash(s) {}

    pair<int, int> get(int l, int r) {
        int h1 = SingleHash1::get(l, r).val();
        int h2 = SingleHash2::get(l, r).val();
        return pair<int, int> (h1, h2);
    }
    pair<int, int> geti(int l, int r) {
        int h1 = SingleHash1::geti(l, r).val();
        int h2 = SingleHash2::geti(l, r).val();
        return pair<int, int> (h1, h2);
    }
    bool ispalindrome(int l, int r) {
        return SingleHash1::ispalindrome(l, r) && SingleHash2::ispalindrome(l, r);
    }
    bool same(int l1, int r1, int l2, int r2) {
        return SingleHash1::same(l1, r1, l2, r2) && SingleHash2::same(l1, r1, l2, r2);
    }
    pair<int, int> MergeFF(int l1, int r1, int l2, int r2) { // Forward and Forward
        int h1 = SingleHash1::MergeFF(l1, r1, l2, r2).val();
        int h2 = SingleHash2::MergeFF(l1, r1, l2, r2).val();
        return pair<int, int> (h1, h2);
    }
    pair<int, int> MergeFR(int l1, int r1, int l2, int r2) { // Forward and reverse
        int h1 = SingleHash1::MergeFR(l1, r1, l2, r2).val();
        int h2 = SingleHash2::MergeFR(l1, r1, l2, r2).val();
        return pair<int, int> (h1, h2);
    }
    pair<int, int> MergeRF(int l1, int r1, int l2, int r2) { // reverse and Forward
        int h1 = SingleHash1::MergeRF(l1, r1, l2, r2).val();
        int h2 = SingleHash2::MergeRF(l1, r1, l2, r2).val();
        return pair<int, int> (h1, h2);
    }
    pair<int, int> MergeRR(int l1, int r1, int l2, int r2) { // reverse and reverse
        int h1 = SingleHash1::MergeRR(l1, r1, l2, r2).val();
        int h2 = SingleHash2::MergeRR(l1, r1, l2, r2).val();
        return pair<int, int> (h1, h2);
    }
};