Refactoring

src/lib.rs

@@ -87,6 +87,7 @@ impl Board {
  neighbor_values.remove(&0);
  neighbor_values
  }
+
  fn get_candidate_values(&self, row: usize, col: usize) -> HashSet<u8> {
  let candidate_values: HashSet<u8> = HashSet::from([1, 2, 3, 4, 5, 6, 7, 8, 9]);
  let neighbor_values = self.get_neighbor_values(row, col);
@@ -111,7 +112,6 @@ impl Board {
  neighbor_values: HashSet<u8>,
  candidate_values: HashSet<u8>,
  ) -> Option<u8> {
-
  let not_candidate_in_neighbors: Vec<u8> = candidate_values
  .into_iter()
  .filter(|x| !neighbor_values.contains(x))
@@ -123,6 +123,27 @@ impl Board {
  None
  }
 
+ pub fn get_value_if_only_one_candidate(candidate_values: &HashSet<u8>) -> Option<u8> {
+ if candidate_values.len() != 1 {
+ return None;
+ }
+ let value = *candidate_values.iter().next().unwrap();
+ Some(value)
+ }
+
+ pub fn get_value_if_not_candidate_in_neighbors(
+ neighbor_values: HashSet<u8>,
+ candidate_values: &HashSet<u8>,
+ ) -> Option<u8> {
+ if let Some(value) = Self::get_value_if_one_value_is_not_possible_in_neighbors(
+ neighbor_values,
+ candidate_values.clone(),
+ ) {
+ return Some(value);
+ }
+ None
+ }
+
  pub fn solve_naive_implementation(&self) -> Board {
  let mut output = Self {
  array: self.array.to_owned(),
@@ -143,30 +164,29 @@ impl Board {
  .get_candidate_values(*row, *col)
  .into_iter()
  .collect();
- if candidate_values.len() == 1 {
-  let value = *candidate_values.iter().next().unwrap();
+
+ if let Some(value) = Board::get_value_if_only_one_candidate(&candidate_values) {
  output.set_value(*row, *col, value);
  continue;
  }
 
- let neighbor_indexes = [
+ let mut found_val = false;
+ for neighbor_ids in [
  output.get_row_neighbor_indexes(*row, *col),
  output.get_col_neighbor_indexes(*row, *col),
  output.get_block_neighbor_indexes(*row, *col),
- ];
- let mut found_val = false;
- for neighbor_ids in neighbor_indexes {
+ ] {
  let neighbor_values: HashSet<u8> = neighbor_ids
  .iter()
  .flat_map(|(r, c)| output.get_candidate_values(*r, *c))
  .collect();
- if let Some(value) = Self::get_value_if_one_value_is_not_possible_in_neighbors(
+ if let Some(value) = Board::get_value_if_not_candidate_in_neighbors(
  neighbor_values,
- candidate_values.clone(),
+ &candidate_values,
  ) {
  output.set_value(*row, *col, value);
  found_val = true;
- break;
+ continue;
  }
  }
  if found_val {