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#include "math/combinatorics/enumeration.hpp"
/** * @brief Enumeration(組み合わせ) */ template< typename T > struct Enumeration { private: static vector< T > _fact, _finv, _inv; inline static void expand(size_t sz) { if(_fact.size() < sz + 1) { int pre_sz = max(1, (int) _fact.size()); _fact.resize(sz + 1, T(1)); _finv.resize(sz + 1, T(1)); _inv.resize(sz + 1, T(1)); for(int i = pre_sz; i <= (int) sz; i++) { _fact[i] = _fact[i - 1] * T(i); } _finv[sz] = T(1) / _fact[sz]; for(int i = (int) sz - 1; i >= pre_sz; i--) { _finv[i] = _finv[i + 1] * T(i + 1); } for(int i = pre_sz; i <= (int) sz; i++) { _inv[i] = _finv[i] * _fact[i - 1]; } } } public: explicit Enumeration(size_t sz = 0) { expand(sz); } static inline T fact(int k) { expand(k); return _fact[k]; } static inline T finv(int k) { expand(k); return _finv[k]; } static inline T inv(int k) { expand(k); return _inv[k]; } static T P(int n, int r) { if(r < 0 || n < r) return 0; return fact(n) * finv(n - r); } static T C(int p, int q) { if(q < 0 || p < q) return 0; return fact(p) * finv(q) * finv(p - q); } static T H(int n, int r) { if(n < 0 || r < 0) return 0; return r == 0 ? 1 : C(n + r - 1, r); } }; template< typename T > vector< T > Enumeration< T >::_fact = vector< T >(); template< typename T > vector< T > Enumeration< T >::_finv = vector< T >(); template< typename T > vector< T > Enumeration< T >::_inv = vector< T >();
#line 1 "math/combinatorics/enumeration.hpp" /** * @brief Enumeration(組み合わせ) */ template< typename T > struct Enumeration { private: static vector< T > _fact, _finv, _inv; inline static void expand(size_t sz) { if(_fact.size() < sz + 1) { int pre_sz = max(1, (int) _fact.size()); _fact.resize(sz + 1, T(1)); _finv.resize(sz + 1, T(1)); _inv.resize(sz + 1, T(1)); for(int i = pre_sz; i <= (int) sz; i++) { _fact[i] = _fact[i - 1] * T(i); } _finv[sz] = T(1) / _fact[sz]; for(int i = (int) sz - 1; i >= pre_sz; i--) { _finv[i] = _finv[i + 1] * T(i + 1); } for(int i = pre_sz; i <= (int) sz; i++) { _inv[i] = _finv[i] * _fact[i - 1]; } } } public: explicit Enumeration(size_t sz = 0) { expand(sz); } static inline T fact(int k) { expand(k); return _fact[k]; } static inline T finv(int k) { expand(k); return _finv[k]; } static inline T inv(int k) { expand(k); return _inv[k]; } static T P(int n, int r) { if(r < 0 || n < r) return 0; return fact(n) * finv(n - r); } static T C(int p, int q) { if(q < 0 || p < q) return 0; return fact(p) * finv(q) * finv(p - q); } static T H(int n, int r) { if(n < 0 || r < 0) return 0; return r == 0 ? 1 : C(n + r - 1, r); } }; template< typename T > vector< T > Enumeration< T >::_fact = vector< T >(); template< typename T > vector< T > Enumeration< T >::_finv = vector< T >(); template< typename T > vector< T > Enumeration< T >::_inv = vector< T >();