Crate permutations_iter 

Generate permutations iteratively without recursion.

Permutations.of(n) function generates an iterator instance for permutations of 0..n.

Permutations.next() uses Steinhaus-Johnson-Trotter algorithm with Even’s modification to generate the next permutation in $O(n)$ time.

Each iterator is one-way. You need to construct a new one for iterating again.

Structs

Permutations

Implements Iterator.

Functions

inverse_perm

Generates the inverse permutation. Has $O(n)$ time complexity.