combinations : Java Glossary

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combinations
If you have a set of objects and select some of them, that selection without regard to their order is called a combination. If you have n objects there are 2n (2 to the nth power) possible combinations ranging from none present to all present. If you consider all the binary numbers ranging from 0 to 2n-1, and look at the individual bits, they map the possible combinations, 1=present 0=absent. So to generate all possible 16-bit quantities just use a for loop, for ( int i=0; i < 65535; i++).
Example Sample Code Links

Example

E.g what are the possible combinations of three objects a b c:
0 000 _
1 001 c
2 010 b
3 011 bc
4 100 a
5 101 ac
6 110 ab
7 111 abc

Sample Code

Here is an implementation of the Dijkstra algorithm for permutations and also a combinations algorithm: view
knapsack problem
Merriam Park Combinations algorithm
permutation
pseudo-random numbers
Uncommon Maths: a library of combination generators
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