Submission #3805331


Source Code Expand

#include <algorithm>
#include <array>
#include <bitset>
#include <complex>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <set>
#include <stack>
#include <unordered_map>
#include <unordered_set>
#include <queue>

using namespace std;

struct BoolName : numpunct<char> {
  string t, f;
  BoolName (string t = "Yes", string f = "No") : t(t), f(f) {}
  string do_truename() const {return t;}
  string do_falsename() const {return f;}
};

struct Initializer {
  Initializer() {
    cin.tie(0);
    ios::sync_with_stdio(0);
    cout << fixed << setprecision(15) << boolalpha;
    cout.imbue(locale(cout.getloc(), new BoolName));
  }
} initializer;

template<typename T> istream& operator>>(istream &s, vector<T> &v) {
  for (T &t : v) s >> t;
  return s;
}

template<typename T> ostream& operator<<(ostream &s, const vector<T> &v) {
  for (const T &t : v) s << t << endl;
  return s;
}

void set_bool_name(string t, string f) {
  cout.imbue(locale(cout.getloc(), new BoolName(t, f)));
}

template<typename T> int least_bit(T n) {
  static_assert(sizeof(T) == 4 || sizeof(T) == 8, "unsupported size");
  if (sizeof(T) == 4) return __builtin_ffs(n) - 1;
  if (sizeof(T) == 8) return __builtin_ffsll(n) - 1;
}

// n must be greater than 0.
template<typename T> int least_bit_fast(T n) {
  static_assert(sizeof(T) == 4 || sizeof(T) == 8, "unsupported size");
  if (sizeof(T) == 4) return __builtin_ctz(n);
  if (sizeof(T) == 8) return __builtin_ctzll(n);
}

template<typename T> int most_bit(T n) {
  static_assert(sizeof(T) == 4 || sizeof(T) == 8, "unsupported size");
  if (sizeof(T) == 4) return n ? 31 - __builtin_clz(n) : -1;
  if (sizeof(T) == 8) return n ? 63 - __builtin_clzll(n) : -1;
}

template<typename T> int count_bit(T n) {
  static_assert(sizeof(T) == 4 || sizeof(T) == 8, "unsupported size");
  if (sizeof(T) == 4) return __builtin_popcount(n);
  if (sizeof(T) == 8) return __builtin_popcountll(n);
}

template<typename T = double> constexpr T pi() {return acos(T(-1));}

template<typename T> T gcd(T t) {return abs(t);}

template<typename T, typename... S> T gcd(T a, S... s) {
  a = abs(a);
  auto b = gcd(s...);
  if (a == 0 || b == 0) return max(a, b);
  int fa = least_bit_fast(a);
  int fb = least_bit_fast(b);
  a >>= fa;
  b >>= fb;
  while (a != b) {
    auto& c = a > b ? a : b;
    c = abs(a - b);
    c >>= least_bit_fast(c);
  }
  return a << min(fa, fb);
}

template<typename T> T gcd(const vector<T>& v) {
  T g = abs(v[0]);
  for (int i = 1; i < int(v.size()); ++i) g = gcd(g, v[i]);
  return g;
}

template<typename T> T lcm(T t) {return abs(t);}

template<typename T, typename... S> T lcm(T t, S... s) {
  T l = lcm(s...);
  return abs(t) / gcd(t, l) * l;
}

template<typename T> T lcm(const vector<T>& v) {
  T l = abs(v[0]);
  for (int i = 1; i < int(v.size()); ++i) l = lcm(l, v[i]);
  return l;
}

template<typename T> T floor(T a, T b) {
  auto d = div(a, b);
  return d.quot - (d.rem && (a < 0) != (b < 0) ? 1 : 0);
}

template<typename T> T ceil(T a, T b) {
  auto d = div(a, b);
  return d.quot + (d.rem && (a > 0) == (b > 0) ? 1 : 0);
}

template<typename T> T round(T a, T b) {return floor(a + b / 2, b);}

template<typename T> T mod(T a, T b) {
  T c = a % b;
  return c < 0 ? c + abs(b) : c;
}

template<typename T> T factorial(T n) {return n <= 1 ? 1 : factorial(n - 1) * n;}

template<typename T> vector<T> factorial_vector(int n) {
  vector<T> v(n + 1, 1);
  for (int i = 1; i <= n; ++i) v[i] = v[i - 1] * i;
  return v;
}

template<typename T> T square(T n) {return n * n;}

template<typename T> T cube(T n) {return n * n * n;}

template<typename T> T norm(T x1, T y1, T x2, T y2) {return square(x1 - x2) + square(y1 - y2);}

template<typename T> bool isSquare(T n) {return square(T(sqrt(n))) == n;}

template<typename T> T clamp(T v, T l, T u) {return v < l ? l : v > u ? u : v;}

template<typename T> class Addition {
public:
  template<typename V> T operator+(const V& v) const {
    return T(static_cast<const T&>(*this)) += v;
  }
};

template<typename T> class Subtraction {
public:
  template<typename V> T operator-(const V& v) const {
    return T(static_cast<const T&>(*this)) -= v;
  }
};

template<typename T> class Multiplication {
public:
  template<typename V> T operator*(const V& v) const {
    return T(static_cast<const T&>(*this)) *= v;
  }
};

template<typename T> class Division {
public:
  template<typename V> T operator/(const V& v) const {
    return T(static_cast<const T&>(*this)) /= v;
  }
};

template<typename T> class Modulus {
public:
  template<typename V> T operator%(const V& v) const {
    return T(static_cast<const T&>(*this)) %= v;
  }
};

template<typename T> class IndivisibleArithmetic : public Addition<T>, public Subtraction<T>, public Multiplication<T> {};

template<typename T> class Arithmetic : public IndivisibleArithmetic<T>, public Division<T> {};

class Inverse {
private:
  int64_t mod;
  vector<int64_t> inv;
  
public:
  Inverse() {}
  
  Inverse(int64_t mod, int64_t n = 1000000) : mod(mod), inv(n, 1) {for (int i = 2; i < n; ++i) inv[i] = inv[mod % i] * (mod - mod / i) % mod;}
  
  int64_t operator()(int64_t a) const {
    if (a < int(inv.size())) return inv[a];
    int64_t b = mod, x = 1, y = 0;
    while (b) {
      int64_t t = a / b;
      swap(a -= t * b, b);
      swap(x -= t * y, y);
    }
    return x < 0 ? x + mod : x;
  }
};

int64_t inverse(int64_t n, int64_t mod) {
  Inverse inv(mod, 0);
  return inv(n);
}

class Mint : public Arithmetic<Mint> {
private:
  static int64_t mod;
  static Inverse inverse;
  int64_t val;

public:
  Mint() : val(0) {}

  Mint(const int64_t& val) {
    this->val = val % mod;
    if (this->val < 0) this->val += mod;
  }

  static void setMod(const int64_t& m) {
    mod = m;
    inverse = Inverse(m);
  }

  Mint operator-() const { return Mint(val ? mod - val : 0); }

  Mint operator+=(const Mint& m) {
    val += m.val;
    if (val >= mod) val -= mod;
    return *this;
  }

  Mint operator-=(const Mint& m) {
    val -= m.val;
    if (val < 0) val += mod;
    return *this;
  }

  Mint operator*=(const Mint& m) {
    val *= m.val;
    val %= mod;
    return *this;
  }

  Mint operator/=(const Mint& m) {
    val *= inverse(m.val);
    val %= mod;
    return *this;
  }

  Mint operator++() {return *this += 1;}

  Mint operator--() {return *this -= 1;}

  template<typename T> Mint operator-(const T& m) { return Arithmetic<Mint>::operator-(m); }

  explicit operator char() const { return val; }

  explicit operator int() const { return val; }

  explicit operator int64_t() const { return val; }

  Mint identity() const {return 1;}
};

int64_t Mint::mod = 1000000007;
Inverse Mint::inverse(1000000007);

ostream& operator<<(ostream& os, Mint a) {
  os << int64_t(a);
  return os;
}

istream& operator>>(istream& is, Mint& a) {
  int64_t n;
  is >> n;
  a = n;
  return is;
}

Mint operator+(const int& n, const Mint& m) { return m + n; }
Mint operator-(const int& n, const Mint& m) { return -m + n; }
Mint operator*(const int& n, const Mint& m) { return m * n; }
Mint operator/(const int& n, const Mint& m) { return Mint(n) / m; }

Mint operator+(const int64_t& n, const Mint& m) { return m + n; }
Mint operator-(const int64_t& n, const Mint& m) { return -m + n; }
Mint operator*(const int64_t& n, const Mint& m) { return m * n; }
Mint operator/(const int64_t& n, const Mint& m) { return Mint(n) / m; }

int main() {
  int n, m;
  cin >> n >> m;
  if (abs(n - m) > 1) {
    cout << 0 << endl;
    return 0;
  }
  auto f = factorial_vector<Mint>(max(n, m));
  cout << (2 - abs(n - m)) * f[n] * f[m] << endl;
}

Submission Info

Submission Time
Task C - Reconciled?
User not
Language C++14 (GCC 5.4.1)
Score 300
Code Size 7626 Byte
Status AC
Exec Time 22 ms
Memory 8832 KB

Judge Result

Set Name Sample All
Score / Max Score 0 / 0 300 / 300
Status
AC × 4
AC × 16
Set Name Test Cases
Sample s1.txt, s2.txt, s3.txt, s4.txt
All 01.txt, 02.txt, 03.txt, 04.txt, 05.txt, 06.txt, 07.txt, 08.txt, 09.txt, 10.txt, 11.txt, 12.txt, s1.txt, s2.txt, s3.txt, s4.txt
Case Name Status Exec Time Memory
01.txt AC 19 ms 8064 KB
02.txt AC 21 ms 8832 KB
03.txt AC 20 ms 8064 KB
04.txt AC 21 ms 8832 KB
05.txt AC 21 ms 8704 KB
06.txt AC 19 ms 8064 KB
07.txt AC 20 ms 8064 KB
08.txt AC 19 ms 8064 KB
09.txt AC 21 ms 8704 KB
10.txt AC 22 ms 8704 KB
11.txt AC 19 ms 8064 KB
12.txt AC 19 ms 8064 KB
s1.txt AC 19 ms 8064 KB
s2.txt AC 19 ms 8064 KB
s3.txt AC 19 ms 8064 KB
s4.txt AC 22 ms 8832 KB