Files
adventofcode2024/day_07/src/equation/operator_set.rs

84 lines
2.4 KiB
Rust

use std::collections::HashMap;
use std::collections::HashSet;
use std::sync::{LazyLock, Mutex};
#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq)]
pub enum Op {
Multiply,
Add,
}
// type OperatorCache = HashMap<usize, HashSet<Vec<Op>>>;
// static OPERATOR_SET_CACHE: LazyLock<Mutex<OperatorCache>> =
// LazyLock::new(|| Mutex::new(HashMap::new()));
// fn check_operator_set_cache(cache_key: usize) -> Option<HashSet<Vec<Op>>> {
// OPERATOR_SET_CACHE.lock().unwrap().get(&cache_key).cloned()
// }
// fn store_operator_set_in_cache(cache_key: usize, cache_value: HashSet<Vec<Op>>) {
// OPERATOR_SET_CACHE
// .lock()
// .unwrap()
// .insert(cache_key, cache_value);
// }
// fn create_operator_set_recurse(
// operators_permutation_set: &mut HashSet<Vec<Op>>,
// operators: Vec<Op>,
// ) {
// operators_permutation_set.insert(operators.clone());
// if !operators.contains(&Op::Add) {
// return;
// }
// for i in 0..operators.len() {
// if operators[i] == Op::Multiply {
// break;
// }
// let mut new_operators = operators.clone();
// new_operators[i] = Op::Multiply;
// create_operator_set_recurse(operators_permutation_set, new_operators);
// }
// }
// pub fn create_operator_set(num_of_operators: usize) -> HashSet<Vec<Op>> {
// // Check cache
// if let Some(cached_value) = check_operator_set_cache(num_of_operators) {
// return cached_value.clone();
// }
// let mut operator_sets: HashSet<Vec<Op>> = HashSet::new();
// create_operator_set_recurse(&mut operator_sets, vec![Op::Add; num_of_operators]);
// // Store value in cache
// store_operator_set_in_cache(num_of_operators, operator_sets.clone());
// operator_sets
// }
fn create_permutations_recurse(
values: &HashSet<Op>,
len: usize,
permutations: &mut HashSet<Vec<Op>>,
curr_permutation: Vec<Op>,
) {
if curr_permutation.len() == len {
permutations.insert(curr_permutation);
return;
}
for v in values {
let mut next_permutation = curr_permutation.clone();
next_permutation.push(*v);
create_permutations_recurse(values, len, permutations, next_permutation);
}
}
pub fn create_permutations(set: HashSet<Op>, len: usize) -> HashSet<Vec<Op>> {
let mut permutations = HashSet::new();
create_permutations_recurse(&set, len, &mut permutations, vec![]);
permutations
}