Subsets Class Reference

Bijective integer encoding of q-subsets of {0, ..., n-1} via binomial(a_0, 1) + binomial(a_1, 2) + ... + binomial(a_{q-1}, q). More...

#include <comb.hpp>

Public Member Functions
	Subsets (size_t n, size_t p)
	~Subsets ()
bool	isValid (const Subset &a)
size_t	encode (const Subset &a)
size_t	encodeBoundary (size_t index, const Subset &a)
void	decode (size_t val, Subset &result)

Static Public Member Functions
static void	show (std::ostream &o, const Subset &a)
static bool	increment (size_t n, Subset &s)
static bool	increment (size_t n, size_t subset_size, size_t *subset)
static bool	isValid (size_t nElements, size_t subsetSize, const size_t *a)
static bool	isValid (size_t nElements, size_t subsetSize, const int *a)
static int	concatenateSubsets (const Subset &s, const Subset &t, Subset &result)

Private Member Functions
size_t	binom (size_t n, size_t p)

Private Attributes
size_t **	mTable
size_t	mNumElements
size_t	mMaxSubsetSize

Detailed Description

Bijective integer encoding of q-subsets of {0, ..., n-1} via binomial(a_0, 1) + binomial(a_1, 2) + ... + binomial(a_{q-1}, q).

Note

AI-generated documentation. Verify against the source before relying on it.

Constructed with maximum bounds (n, p); supports encoding and decoding of q-subsets for all q <= p. The encoding does not depend on n, so the same index space scales as the underlying set grows. Throws if a result would not fit in size_t. Used wherever the engine enumerates exterior-style subsets without allocating an explicit table.

Definition at line 73 of file comb.hpp.

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The documentation for this class was generated from the following files:

• Macaulay2/e/comb.hpp
• Macaulay2/e/comb.cpp