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46 lines
825 B
46 lines
825 B
use crate::List::*;
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enum List {
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Cons(u32, Box<List>),
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Nil,
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}
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impl List {
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fn new() -> List {
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Nil
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}
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fn prepend(self, elem: u32) -> List {
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Cons(elem, Box::new(self))
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}
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fn len(&self) -> u32 {
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match *self {
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Cons(_, ref tail) => 1 + tail.len(),
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Nil => 0,
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}
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}
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fn stringify(&self) -> String {
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match *self {
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Cons(head, ref tail) => {
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format!("{}, {}", head, tail.stringify())
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}
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Nil => {
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format!("Nil")
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}
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}
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}
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}
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fn main() {
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let mut list = List::new();
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list = list.prepend(1);
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list = list.prepend(2);
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list = list.prepend(3);
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println!("linked list has length: {}", list.len());
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println!("{}", list.stringify());
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}
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