All possible permutations of a string - Total number of permutations of a given word taking all n letters is n!.
For example, the word post will give 24 possible permutations inclusive of the original word (post).
This snippet here doesn't exactly output permutations of a string, but its indexes - which should correspond to the array indexes.
Now, its pretty obvious why I had the permutations written to a file instead of console output. 9! is 362,880 but 10! is 10 times 9! which is more than 3.5 million lines of text.
Update : I have ported the C code in Java with some modifications in the way output is handled. This is much safer than that big for loop.
PS: I wrote this half a decade ago but never documented it. I'll try to update it with an explanation soon.
|algorithms, c++, Java||Friday, July 06, 2007|