CompositionMaker Class Reference

Generator of all the compositions of an integer in a specific number of parts. More...

#include <CompositionMaker.h>

Public Member Functions
	CompositionMaker (unsigned int n, unsigned int k)
	Constructs a generator of all the compositions of n into k parts.
bool	goToNextComposition ()
	Change the current composition to the next composition. More...
const std::pair< std::pair< int, int >, std::pair< int, int > > &	changeFromPreviousComposition () const
	Returns the difference between the previous compositon and the current composition. More...
const std::vector< unsigned int > &	currentComposition () const
	Returns the current composition held by the generator.

Detailed Description

Generator of all the compositions of an integer in a specific number of parts.

This class can be used to generate iteratively all the compositions of an integer \(n\) in a specific number of parts \(k\), that is all the \( k \)-uple \((a_1, ..., a_k)\) such that \( \sum_{i=1}^k a_i = n \). Furthermore, two consecutive compositions only differ by one unitary operation: only one unit has been transfered from one \( a_i\) to another \( a_j \).

Member Function Documentation

changeFromPreviousComposition()

const std::pair<std::pair<int,int>, std::pair<int,int> >& CompositionMaker::changeFromPreviousComposition

(

)

const

Returns the difference between the previous compositon and the current composition.

Returns

A pair of pairs of ints. The first pair indicates which \(a_i\) has decreased and its former value, the second indicates which \( a_i \) has increased and its new value.

goToNextComposition()

bool CompositionMaker::goToNextComposition

(

)

Change the current composition to the next composition.

Returns false when the generator is depleted and true otherwise.

Returns

A boolean indicating if the generator is depleted.

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

• include/netbuilder/CompositionMaker.h