Boost.Combinations

Boost.Combinations is a library for combinations and permutaions.  It works like C++ std::next_permuation(), enumerating one selecting to another.  Except combinations, partial permutaions were also supported.


A) intro:

Combinations:  For example, select 2 elements from {1, 2, 3}.  We got {1, 2}, {1, 3}, {2, 3}.

Permutaions:  For example, select 2 elements from {1, 2, 3}.  We got {1, 2}, {1, 3}, {2, 1}, {2, 3}, {3, 1}, {3, 2}.


B) headers:

combinations.hpp:  main header, contains combinations and permutaions  enumerating functions.

combinations_init.hpp:  functions that help to initialize a sequence to a valid input sequence.


C) main function:

next_combination(first, middle, last)
prev_combination(first, middle, last)
next_permutation(first, middle, last)
prev_permutation(first, middle, last)