RollingHash

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RollingHash rh(s);

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rh.get(l,r)

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struct RollingHash {
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  vector<uint> hashed, power;
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  const uint mod = 0x1fffffffffffffff, base = chrono::duration_cast<chrono::microseconds>(chrono::system_clock::now().time_since_epoch()).count() % mod;
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  static constexpr uint mask(int a) { return (1ULL << a) - 1; }
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  inline uint mul(uint a, uint b) const {
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    __uint128_t ans = __uint128_t(a) * b;
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    ans = (ans >> 61) + (ans & mod);
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    if (ans >= mod)
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      ans -= mod;
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    return ans;
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  }
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  RollingHash(const string &s) {
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    int n = s.size();
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    hashed.assign(n + 1, 0);
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    power.assign(n + 1, 0);
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    power[0] = 1;
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    for (int i = 0; i < n; i++) {
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      power[i + 1] = mul(power[i], base);
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      hashed[i + 1] = mul(hashed[i], base) + s[i];
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      if (hashed[i + 1] >= mod)
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        hashed[i + 1] -= mod;
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    }
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  }
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  uint get(int l, int r) const {
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    uint ret = hashed[r] + mod - mul(hashed[l], power[r - l]);
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    if (ret >= mod)
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      ret -= mod;
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    return ret;
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  }
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  uint connect(uint h1, uint h2, int h2len) const {
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    uint ret = mul(h1, power[h2len]) + h2;
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    if (ret >= mod)
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      ret -= mod;
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    return ret;
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  }
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  void connect(const string &s) {
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    int n = hashed.size() - 1, m = s.size();
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    hashed.resize(n + m + 1);
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    power.resize(n + m + 1);
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    for (int i = n; i < n + m; i++) {
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      power[i + 1] = mul(power[i], base);
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      hashed[i + 1] = mul(hashed[i], base) + s[i - n];
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      if (hashed[i + 1] >= mod)
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        hashed[i + 1] -= mod;
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    }
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  }
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  int LCP(const RollingHash &b, int l1, int r1, int l2, int r2) {
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    int len = min(r1 - l1, r2 - l2);
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    int low = -1, high = len + 1;
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    while (high - low > 1) {
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      int mid = (low + high) / 2;
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      if (get(l1, l1 + mid) == b.get(l2, l2 + mid))
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        low = mid;
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      else
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        high = mid;
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    }
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    return low;
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  }
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};