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ID题目提交者结果用时内存语言文件大小提交时间测评时间
#334050#8047. DFS Order 4hos_lyricAC ✓214ms6672kbC++147.5kb2024-02-21 04:47:192024-02-21 04:47:20

Judging History

你现在查看的是最新测评结果

  • [2024-02-21 04:47:20]
  • 评测
  • 测评结果:AC
  • 用时:214ms
  • 内存:6672kb
  • [2024-02-21 04:47:19]
  • 提交

answer

#include <cassert>
#include <cmath>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <functional>
#include <iostream>
#include <limits>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;

using Int = long long;

template <class T1, class T2> ostream &operator<<(ostream &os, const pair<T1, T2> &a) { return os << "(" << a.first << ", " << a.second << ")"; };
template <class T> ostream &operator<<(ostream &os, const vector<T> &as) { const int sz = as.size(); os << "["; for (int i = 0; i < sz; ++i) { if (i >= 256) { os << ", ..."; break; } if (i > 0) { os << ", "; } os << as[i]; } return os << "]"; }
template <class T> void pv(T a, T b) { for (T i = a; i != b; ++i) cerr << *i << " "; cerr << endl; }
template <class T> bool chmin(T &t, const T &f) { if (t > f) { t = f; return true; } return false; }
template <class T> bool chmax(T &t, const T &f) { if (t < f) { t = f; return true; } return false; }
#define COLOR(s) ("\x1b[" s "m")

////////////////////////////////////////////////////////////////////////////////
// Barrett
struct ModInt {
  static unsigned M;
  static unsigned long long NEG_INV_M;
  static void setM(unsigned m) { M = m; NEG_INV_M = -1ULL / M; }
  unsigned x;
  ModInt() : x(0U) {}
  ModInt(unsigned x_) : x(x_ % M) {}
  ModInt(unsigned long long x_) : x(x_ % M) {}
  ModInt(int x_) : x(((x_ %= static_cast<int>(M)) < 0) ? (x_ + static_cast<int>(M)) : x_) {}
  ModInt(long long x_) : x(((x_ %= static_cast<long long>(M)) < 0) ? (x_ + static_cast<long long>(M)) : x_) {}
  ModInt &operator+=(const ModInt &a) { x = ((x += a.x) >= M) ? (x - M) : x; return *this; }
  ModInt &operator-=(const ModInt &a) { x = ((x -= a.x) >= M) ? (x + M) : x; return *this; }
  ModInt &operator*=(const ModInt &a) {
    const unsigned long long y = static_cast<unsigned long long>(x) * a.x;
    const unsigned long long q = static_cast<unsigned long long>((static_cast<unsigned __int128>(NEG_INV_M) * y) >> 64);
    const unsigned long long r = y - M * q;
    x = r - M * (r >= M);
    return *this;
  }
  ModInt &operator/=(const ModInt &a) { return (*this *= a.inv()); }
  ModInt pow(long long e) const {
    if (e < 0) return inv().pow(-e);
    ModInt a = *this, b = 1U; for (; e; e >>= 1) { if (e & 1) b *= a; a *= a; } return b;
  }
  ModInt inv() const {
    unsigned a = M, b = x; int y = 0, z = 1;
    for (; b; ) { const unsigned q = a / b; const unsigned c = a - q * b; a = b; b = c; const int w = y - static_cast<int>(q) * z; y = z; z = w; }
    assert(a == 1U); return ModInt(y);
  }
  ModInt operator+() const { return *this; }
  ModInt operator-() const { ModInt a; a.x = x ? (M - x) : 0U; return a; }
  ModInt operator+(const ModInt &a) const { return (ModInt(*this) += a); }
  ModInt operator-(const ModInt &a) const { return (ModInt(*this) -= a); }
  ModInt operator*(const ModInt &a) const { return (ModInt(*this) *= a); }
  ModInt operator/(const ModInt &a) const { return (ModInt(*this) /= a); }
  template <class T> friend ModInt operator+(T a, const ModInt &b) { return (ModInt(a) += b); }
  template <class T> friend ModInt operator-(T a, const ModInt &b) { return (ModInt(a) -= b); }
  template <class T> friend ModInt operator*(T a, const ModInt &b) { return (ModInt(a) *= b); }
  template <class T> friend ModInt operator/(T a, const ModInt &b) { return (ModInt(a) /= b); }
  explicit operator bool() const { return x; }
  bool operator==(const ModInt &a) const { return (x == a.x); }
  bool operator!=(const ModInt &a) const { return (x != a.x); }
  friend std::ostream &operator<<(std::ostream &os, const ModInt &a) { return os << a.x; }
};
unsigned ModInt::M;
unsigned long long ModInt::NEG_INV_M;
// !!!Use ModInt::setM!!!
////////////////////////////////////////////////////////////////////////////////

using Mint = ModInt;

constexpr int LIM_INV = 2010;
Mint inv[LIM_INV], fac[LIM_INV], invFac[LIM_INV];

void prepare() {
  inv[1] = 1;
  for (int i = 2; i < LIM_INV; ++i) {
    inv[i] = -((Mint::M / i) * inv[Mint::M % i]);
  }
  fac[0] = invFac[0] = 1;
  for (int i = 1; i < LIM_INV; ++i) {
    fac[i] = fac[i - 1] * i;
    invFac[i] = invFac[i - 1] * inv[i];
  }
}
Mint binom(Int n, Int k) {
  if (n < 0) {
    if (k >= 0) {
      return ((k & 1) ? -1 : +1) * binom(-n + k - 1, k);
    } else if (n - k >= 0) {
      return (((n - k) & 1) ? -1 : +1) * binom(-k - 1, n - k);
    } else {
      return 0;
    }
  } else {
    if (0 <= k && k <= n) {
      assert(n < LIM_INV);
      return fac[n] * invFac[k] * invFac[n - k];
    } else {
      return 0;
    }
  }
}


namespace exper {
int N;
vector<int> P;
map<vector<int>, vector<int>> vis;

vector<int> us;
bool decide() {
  vector<int> par(N, -1);
  // trying to attach w to u, last sibling is v
  int u = 0, v = -1;
  for (int j = 1; j < N; ++j) {
    const int w = us[j];
    for (; u > w || v > w; ) {
      v = u;
      u = par[u];
      if (!~u) return false;
    }
    par[w] = u;
    u = w;
    v = -1;
  }
  return true;
}

void dfs(int u) {
  us.push_back(u);
  for (int v = u + 1; v < N; ++v) if (u == P[v]) {
    dfs(v);
  }
}

void rec(int u) {
  if (u == N) {
    us.clear();
    dfs(0);
    vis[us] = P;
  } else {
    for (P[u] = 0; P[u] < u; ++P[u]) {
      rec(u + 1);
    }
  }
}

void run() {
  for (N = 1; N <= 10; ++N) {
    P.assign(N, -1);
    vis.clear();
    rec(1);
    for (const auto &kv : vis) {
      cerr << kv.first << " " << kv.second << endl;
    }
    
    us.resize(N);
    for (int u = 0; u < N; ++u) us[u] = u;
    do {
      auto it = vis.find(us);
      const bool brt = (it != vis.end());
      const bool res = decide();
      if (brt != res) {
        cerr << "FAIL: " << us << ": " << brt << " " << res << endl;
      }
      assert(brt == res);
    } while (next_permutation(us.begin() + 1, us.end()));
    
    cerr << "DONE N = " << N << ": " << vis.size() << endl;
  }
}
}  // exper


/*
  tree generated by the greedy decision
  
  attach w to u, last sibling is v: u < w && v < w
  if v = -1:
    in previous iteration u < w
    ==> in previous iteration v > w
    i.e. (rightmost child of v) > w
  this condition is sufficient
  
  PIE for "(rightmost child of v) > w"
  -> constraints form a tree
*/

// size, size added to last child
Mint dp[810][810];

int main() {
  // exper::run();
  
  int N, MO;
  for (; ~scanf("%d%d", &N, &MO); ) {
    Mint::setM(MO);
    prepare();
    
    memset(dp, 0, sizeof(dp));
    dp[1][0] = 1;
    for (int n = 2; n <= N; ++n) {
      for (int k = 0; n + k <= N; ++k) {
        /*
        // casework on leftmost subtree...
        // single
        dp[n][k] += inv[n - 1 + k] * dp[n - 1][0];
        // multiple
        for (int m = 2; m < n - 1; ++m) {
          dp[n][k] += inv[n - 1 + k] * dp[m][0] * dp[n - m][k];
          dp[n][k] -= inv[n - 1 + k] * dp[m][n - 1 + k - m] * dp[n - m][k];
        }
        */
        dp[n][k] += dp[n - 1][0];
        for (int m = 2; m < n - 1; ++m) {
          dp[n][k] += (dp[m][0] - dp[m][n - 1 + k - m]) * dp[n - m][k];
        }
        dp[n][k] *= inv[n - 1 + k];
      }
// cerr<<n<<": ";for(int k=0;n+k<=N;++k)cerr<<(fac[n+k-1]*dp[n][k])<<" ";cerr<<endl;
    }
    const Mint ans = fac[N - 1] * dp[N][0];
    printf("%u\n", ans.x);
  }
  return 0;
}

这程序好像有点Bug,我给组数据试试?

详细

Test #1:

score: 100
Accepted
time: 0ms
memory: 6400kb

input:

4 114514199

output:

2

result:

ok 1 number(s): "2"

Test #2:

score: 0
Accepted
time: 2ms
memory: 6668kb

input:

10 998244353

output:

11033

result:

ok 1 number(s): "11033"

Test #3:

score: 0
Accepted
time: 0ms
memory: 6604kb

input:

100 1000000007

output:

270904395

result:

ok 1 number(s): "270904395"

Test #4:

score: 0
Accepted
time: 178ms
memory: 6656kb

input:

756 1001338769

output:

901942543

result:

ok 1 number(s): "901942543"

Test #5:

score: 0
Accepted
time: 204ms
memory: 6344kb

input:

793 1009036033

output:

301770320

result:

ok 1 number(s): "301770320"

Test #6:

score: 0
Accepted
time: 160ms
memory: 6400kb

input:

759 1005587659

output:

846376219

result:

ok 1 number(s): "846376219"

Test #7:

score: 0
Accepted
time: 188ms
memory: 6340kb

input:

773 1007855479

output:

1398019

result:

ok 1 number(s): "1398019"

Test #8:

score: 0
Accepted
time: 176ms
memory: 6380kb

input:

751 1006730639

output:

321287237

result:

ok 1 number(s): "321287237"

Test #9:

score: 0
Accepted
time: 174ms
memory: 6672kb

input:

778 1007760653

output:

430322899

result:

ok 1 number(s): "430322899"

Test #10:

score: 0
Accepted
time: 212ms
memory: 6668kb

input:

798 1007543827

output:

688720826

result:

ok 1 number(s): "688720826"

Test #11:

score: 0
Accepted
time: 206ms
memory: 6372kb

input:

796 1004841413

output:

258829347

result:

ok 1 number(s): "258829347"

Test #12:

score: 0
Accepted
time: 194ms
memory: 6400kb

input:

775 1005185189

output:

744278608

result:

ok 1 number(s): "744278608"

Test #13:

score: 0
Accepted
time: 214ms
memory: 6624kb

input:

800 1006012831

output:

508549367

result:

ok 1 number(s): "508549367"

Test #14:

score: 0
Accepted
time: 2ms
memory: 6400kb

input:

1 1001338769

output:

1

result:

ok 1 number(s): "1"

Test #15:

score: 0
Accepted
time: 1ms
memory: 6392kb

input:

2 1001338769

output:

1

result:

ok 1 number(s): "1"

Test #16:

score: 0
Accepted
time: 1ms
memory: 6652kb

input:

9 1009036033

output:

1780

result:

ok 1 number(s): "1780"

Test #17:

score: 0
Accepted
time: 0ms
memory: 6376kb

input:

14 1001338769

output:

43297358

result:

ok 1 number(s): "43297358"

Extra Test:

score: 0
Extra Test Passed