45 lines
1.0 KiB
Rust
45 lines
1.0 KiB
Rust
fn main() {
|
|
let examples = vec!["broood", "bananaaa", "hiphophiphop"];
|
|
for example in examples {
|
|
let encoded = encode(example);
|
|
let decoded = decode(&encoded);
|
|
println!(
|
|
"{} encodes to {:?} decodes to {}",
|
|
example, encoded, decoded
|
|
);
|
|
}
|
|
}
|
|
|
|
fn get_symbols() -> Vec<u8> {
|
|
(b'a'..b'z').collect()
|
|
}
|
|
|
|
fn encode(input: &str) -> Vec<usize> {
|
|
input
|
|
.as_bytes()
|
|
.iter()
|
|
.fold((Vec::new(), get_symbols()), |(mut o, mut s), x| {
|
|
let i = s.iter().position(|c| c == x).unwrap();
|
|
let c = s.remove(i);
|
|
s.insert(0, c);
|
|
o.push(i);
|
|
(o, s)
|
|
})
|
|
.0
|
|
}
|
|
|
|
fn decode(input: &[usize]) -> String {
|
|
input
|
|
.iter()
|
|
.fold((Vec::new(), get_symbols()), |(mut o, mut s), x| {
|
|
o.push(s[*x]);
|
|
let c = s.remove(*x);
|
|
s.insert(0, c);
|
|
(o, s)
|
|
})
|
|
.0
|
|
.into_iter()
|
|
.map(|c| c as char)
|
|
.collect()
|
|
}
|