Submission #673629

#TimeUsernameProblemLanguageResultExecution timeMemory
673629peijarCopy and Paste 3 (JOI22_copypaste3)C++17
1 / 100
1098 ms21604 KiB
#include <bits/stdc++.h>
#define int long long
using namespace std;

template <const int32_t MOD> struct ModInt {
  int32_t x;
  ModInt() : x(0) {}
  ModInt(long long u) : x(u % MOD) {
    if (x < 0)
      x += MOD;
  }
  friend bool operator==(const ModInt &a, const ModInt &b) {
    return a.x == b.x;
  }
  friend bool operator!=(const ModInt &a, const ModInt &b) {
    return a.x != b.x;
  }
  friend bool operator<(const ModInt &a, const ModInt &b) { return a.x < b.x; }
  friend bool operator>(const ModInt &a, const ModInt &b) { return a.x > b.x; }
  friend bool operator<=(const ModInt &a, const ModInt &b) {
    return a.x <= b.x;
  }
  friend bool operator>=(const ModInt &a, const ModInt &b) {
    return a.x >= b.x;
  }
  static ModInt sign(long long k) {
    return ((k & 1) ? ModInt(MOD - 1) : ModInt(1));
  }

  ModInt &operator+=(const ModInt &m) {
    x += m.x;
    if (x >= MOD)
      x -= MOD;
    return *this;
  }
  ModInt &operator-=(const ModInt &m) {
    x -= m.x;
    if (x < 0LL)
      x += MOD;
    return *this;
  }
  ModInt &operator*=(const ModInt &m) {
    x = (1LL * x * m.x) % MOD;
    return *this;
  }

  friend ModInt operator-(const ModInt &a) {
    ModInt res(a);
    if (res.x)
      res.x = MOD - res.x;
    return res;
  }
  friend ModInt operator+(const ModInt &a, const ModInt &b) {
    return ModInt(a) += ModInt(b);
  }
  friend ModInt operator-(const ModInt &a, const ModInt &b) {
    return ModInt(a) -= ModInt(b);
  }
  friend ModInt operator*(const ModInt &a, const ModInt &b) {
    return ModInt(a) *= ModInt(b);
  }

  static long long fp(long long u, long long k) {
    long long res = 1LL;
    while (k > 0LL) {
      if (k & 1LL)
        res = (res * u) % MOD;
      u = (u * u) % MOD;
      k /= 2LL;
    }
    return res;
  }

  static constexpr int mod() { return MOD; }

  ModInt fastpow(long long k) { return ModInt(fp(x, k)); }
  ModInt inv() {
    assert(x);
    return ModInt(fp(x, MOD - 2));
  }
  ModInt &operator/=(const ModInt &m) { return *this *= ModInt(m).inv(); }
  friend ModInt operator/(const ModInt &a, const ModInt &b) {
    return ModInt(a) *= ModInt(b).inv();
  }

  friend ostream &operator<<(ostream &out, const ModInt &a) {
    return out << a.x;
  }
  friend istream &operator>>(istream &in, ModInt &a) { return in >> a.x; }
};

const int MOD = 1e9 + 9;
using Mint = ModInt<MOD>;

const int BASE = 330;

const int MAXN = 2501;
const int INF = 1e18;

Mint powBase[MAXN], invPow[MAXN];
int N, costAdd, costCut, costPaste;
string s;
vector<Mint> prefPow;
map<Mint, vector<int>> occs;

map<Mint, int> cache;

int solve(int l, int r) {
  if (l == r)
    return 0;
  if (l + 1 == r)
    return costAdd;

  Mint curHsh = (prefPow[r] - prefPow[l]) * invPow[l];
  if (cache.count(curHsh))
    return cache[curHsh];
  int &ret = cache[curHsh];
  ret = INF;

  ret = min(ret, solve(l + 1, r) + costAdd);
  ret = min(ret, (r - l) * costAdd);
  for (int len = 1; len < r - l; ++len) {
    Mint x = (prefPow[l + len] - prefPow[l]) * invPow[l];
    vector<int> &pos = occs[x];
    int nbOcc = 0;
    int cur = l;
    while (cur + len <= r) {
      nbOcc++;
      int id = lower_bound(pos.begin(), pos.end(), cur + len) - pos.begin();
      if (id == (int)pos.size())
        break;
      cur = pos[id];
    }
    ret = min(ret, len * costAdd + costCut + costPaste * nbOcc +
                       (r - l - len * nbOcc) * costAdd);
  }
  return ret;
}

signed main(void) {
  ios_base::sync_with_stdio(false);
  cin.tie(0);

  powBase[0] = 1;
  for (int i = 1; i < MAXN; ++i)
    powBase[i] = powBase[i - 1] * BASE;
  invPow[MAXN - 1] = powBase[MAXN - 1].inv();
  for (int i = MAXN - 1; i > 0; --i)
    invPow[i - 1] = invPow[i] * BASE;

  cin >> N >> s >> costAdd >> costCut >> costPaste;
  prefPow.resize(N + 1);

  for (int i = 0; i < N; ++i)
    prefPow[i + 1] = prefPow[i] + powBase[i] * s[i];

  for (int deb = 0; deb < N; ++deb)
    for (int fin = deb + 1; fin <= N; ++fin)
      occs[(prefPow[fin] - prefPow[deb]) * invPow[deb]].push_back(deb);
  cout << solve(0, N) << endl;
  return 0;

  vector<vector<int>> dp(N + 1, vector<int>(N + 1, INF));

  for (int deb = N; deb >= 0; --deb) {
    vector<vector<pair<int, int>>> updates(N + 1);
    for (int len = 1; len < N - deb; ++len) {
      int nbOcc = 0;
      Mint x = (prefPow[deb + len] - prefPow[deb]) * invPow[deb];
      int curPos = deb;
      auto &vec = occs[x];
      while (true) {
        nbOcc++;
        updates[curPos + len].emplace_back(len, nbOcc);
        int id =
            lower_bound(vec.begin(), vec.end(), curPos + len) - vec.begin();
        if (id == (int)vec.size())
          break;
        curPos = vec[id];
      }
    }

    for (int fin = deb; fin <= N; ++fin) {
      int &cur = dp[deb][fin];
      if (deb == fin) {
        cur = 0;
        continue;
      }
      cur = min(cur, dp[deb + 1][fin] + costAdd);
      cur = min(cur, dp[deb][fin - 1] + costAdd);
      for (auto [len, nbOcc] : updates[fin])
        cur = min(cur, nbOcc * costPaste + costCut + dp[deb][deb + len] +
                           (fin - deb - len * nbOcc) * costAdd);
    }
  }
  cout << dp[0][N] << endl;
}
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