Struct FinExtPerm 

pub struct FinExtPerm {
    pub perm: Vec<usize>,
}

A permutation of {0, ..., n-1} stored as a vector.

Fields

perm: Vec<usize>

The permutation as a map: index i → perm[i].

Implementations

impl FinExtPerm

pub fn identity(n: usize) -> Self

Create the identity permutation on n elements.

pub fn from_vec(v: Vec<usize>) -> Option<Self>

Create a permutation from a vector. Returns None if not a valid permutation.

pub fn len(&self) -> usize

The size of the permutation.

pub fn is_empty(&self) -> bool

Returns true if the permutation is empty.

pub fn apply(&self, i: usize) -> Option<usize>

Apply the permutation to index i.

pub fn compose(&self, other: &Self) -> Option<Self>

Compose self ∘ other (apply other first, then self).

pub fn inverse(&self) -> Self

Compute the inverse permutation.

pub fn sign(&self) -> i32

Compute the sign (parity) of the permutation: +1 for even, -1 for odd.

pub fn cycle_count(&self) -> usize

Count the number of cycles.

pub fn is_derangement(&self) -> bool

Check if this permutation is a derangement (no fixed points).

pub fn order(&self) -> usize

Return the order of the permutation (smallest k > 0 with σ^k = id).

Trait Implementations

impl Clone for FinExtPerm

fn clone(&self) -> FinExtPerm

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for FinExtPerm

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for FinExtPerm

fn eq(&self, other: &FinExtPerm) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for FinExtPerm

impl StructuralPartialEq for FinExtPerm