spoonerustisms.rs

use std::str;
use std::collections::HashSet;

use permutohedron::Heap;

fn main() {
    let original_data = b"abcdefghi".to_vec();
    let mut data = original_data.clone();
    let heap = Heap::new(&mut data);

    let mut permutations = Vec::new();
    for data in heap {
        let s = str::from_utf8(&data).unwrap().to_owned();
        permutations.push(s);
    }

    println!("{:?}", permutations.len());

    let filtered_permutations = permutations.iter().filter(|s| {
        !original_data
            .iter()
            .zip(s.as_bytes())
            .any(|(orig_c, c)| orig_c == c)
    }).collect::<HashSet<_>>();

    println!("{:?}", filtered_permutations.len())
}