Simplify Iterator(s) for BST

main
sgoudham 3 years ago
parent 94a03c7863
commit cdfe0d44a3
Signed by: hammy
GPG Key ID: 44E818FD5457EEA4

@ -1,12 +1,8 @@
use std::cmp::Ordering;
use std::collections::VecDeque;
use std::vec::IntoIter;
type Child<T> = Option<Box<Node<T>>>;
pub struct IntoPreOrderIter<T>(T);
pub struct IntoInOrderIter<T>(T);
pub struct IntoPostOrderIter<T>(T);
#[derive(Debug)]
pub struct BST<T: Ord> {
root: Child<T>,
@ -84,27 +80,27 @@ impl<T: Ord> Node<T> {
}
}
fn pre_order_traversal(node: Child<T>, pre_order: &mut VecDeque<T>) {
fn pre_order_traversal(node: Child<T>, pre_order: &mut Vec<T>) {
if let Some(node) = node {
pre_order.push_front(node.value);
pre_order.push(node.value);
Self::pre_order_traversal(node.left, pre_order);
Self::pre_order_traversal(node.right, pre_order);
}
}
fn in_order_traversal(node: Child<T>, in_order: &mut VecDeque<T>) {
fn in_order_traversal(node: Child<T>, in_order: &mut Vec<T>) {
if let Some(node) = node {
Self::in_order_traversal(node.left, in_order);
in_order.push_front(node.value);
in_order.push(node.value);
Self::in_order_traversal(node.right, in_order);
}
}
fn post_order_traversal(node: Child<T>, post_order: &mut VecDeque<T>) {
fn post_order_traversal(node: Child<T>, post_order: &mut Vec<T>) {
if let Some(node) = node {
Self::post_order_traversal(node.left, post_order);
Self::post_order_traversal(node.right, post_order);
post_order.push_front(node.value);
post_order.push(node.value);
}
}
}
@ -148,46 +144,22 @@ impl<T: Ord> BST<T> {
}
}
pub fn into_pre_order_iter(self) -> IntoPreOrderIter<VecDeque<T>> {
let mut pre_order = VecDeque::new();
pub fn into_pre_order_iter(self) -> IntoIter<T> {
let mut pre_order = Vec::new();
Node::pre_order_traversal(self.root, &mut pre_order);
IntoPreOrderIter(pre_order)
pre_order.into_iter()
}
pub fn into_in_order_iter(self) -> IntoInOrderIter<VecDeque<T>> {
let mut in_order = VecDeque::new();
pub fn into_in_order_iter(self) -> IntoIter<T> {
let mut in_order = Vec::new();
Node::in_order_traversal(self.root, &mut in_order);
IntoInOrderIter(in_order)
in_order.into_iter()
}
pub fn into_post_order_iter(self) -> IntoPostOrderIter<VecDeque<T>> {
let mut post_order = VecDeque::new();
pub fn into_post_order_iter(self) -> IntoIter<T> {
let mut post_order = Vec::new();
Node::post_order_traversal(self.root, &mut post_order);
IntoPostOrderIter(post_order)
}
}
impl<T: Ord> Iterator for IntoPreOrderIter<VecDeque<T>> {
type Item = T;
fn next(&mut self) -> Option<Self::Item> {
self.0.pop_back()
}
}
impl<T: Ord> Iterator for IntoInOrderIter<VecDeque<T>> {
type Item = T;
fn next(&mut self) -> Option<Self::Item> {
self.0.pop_back()
}
}
impl<T: Ord> Iterator for IntoPostOrderIter<VecDeque<T>> {
type Item = T;
fn next(&mut self) -> Option<Self::Item> {
self.0.pop_back()
post_order.into_iter()
}
}

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