There are several ways to create a tree with nodes that can identify their parent and children in Rust, but one possible process is:
struct Node<T> {
value: T,
parent: Option<Box<Node<T>>>,
children: Vec<Box<Node<T>>>,
}
impl<T> Node<T> {
fn add_child(&mut self, value: T) -> &mut Node<T> {
let child = Box::new(Node {
value: value,
parent: Some(Box::new(self.clone())),
children: Vec::new(),
});
self.children.push(child);
self.children.last_mut().unwrap().as_mut()
}
fn remove_child(&mut self, index: usize) -> T {
let child = self.children.remove(index);
child.parent = None;
child.value
}
fn get_child(&self, index: usize) -> Option<&Node<T>> {
self.children.get(index).map(|child| child.as_ref())
}
fn get_parent(&self) -> Option<&Node<T>> {
self.parent.as_ref().map(|parent| parent.as_ref())
}
fn set_parent(&mut self, parent: Option<Box<Node<T>>>) {
self.parent = parent;
}
}
add_child
method to build the tree recursively by attaching child nodes to their parent nodes.let mut root = Node {
value: "root",
parent: None,
children: Vec::new(),
};
let mut child1 = root.add_child("child1");
let mut child2 = root.add_child("child2");
let mut child11 = child1.add_child("child11");
let mut child12 = child1.add_child("child12");
let mut child21 = child2.add_child("child21");
let mut child22 = child2.add_child("child22");
assert_eq!(root.get_child(0).unwrap().get_child(1).unwrap().value, "child12");
child11.set_parent(Some(Box::new(child2)));
assert!(child11.get_parent().unwrap().value == "child2" && child1.children.len() == 1 && child2.children.len() == 3);
Asked: 2022-06-15 11:00:00 +0000
Seen: 11 times
Last updated: Mar 17 '23