Day 12 - late

Author: Lank891

Day 12 - Rust/README.md

@@ -0,0 +1,4 @@
+# [Day 12](https://adventofcode.com/2021/day/12) in [Rust](https://www.rust-lang.org/)
+
+### Additional dependecies
+* "regex"

Day 12 - Rust/input.txt

@@ -0,0 +1,25 @@
+start-co
+ip-WE
+end-WE
+le-ls
+wt-zi
+end-sz
+wt-RI
+wt-sz
+zi-start
+wt-ip
+YT-sz
+RI-start
+le-end
+ip-sz
+WE-sz
+le-WE
+le-wt
+zi-ip
+RI-zi
+co-zi
+co-le
+WB-zi
+wt-WE
+co-RI
+RI-ip

Day 12 - Rust/main.rs

@@ -0,0 +1,96 @@
+use std::fs;
+use regex::Regex;
+use std::collections::HashSet;
+use std::collections::HashMap;
+use std::time::Instant;
+
+const INPUT_FILE: &str = "./input.txt";
+
+fn is_upper_case(s: &String) -> bool {
+  return s.chars().all(|b| matches!(b, 'A'..='Z'));
+}
+
+fn dfs_part_one(vertex: &String, adj_list: &HashMap<String, HashSet<String>>, mut visited: HashSet<String>) -> i32 {
+  let mut paths = 0;
+
+  if vertex.eq(&"end".to_string()) {
+    return 1;
+  }
+
+  if !is_upper_case(&vertex) {
+    visited.insert(vertex.clone());
+  }
+
+  let neighbours = &adj_list[vertex];
+  let unvisited_neighbours = neighbours.difference(&visited);
+
+  for neighbour in unvisited_neighbours {
+    paths += dfs_part_one(neighbour, adj_list, visited.clone());
+  }
+
+  return paths;
+}
+
+fn dfs_part_two(vertex: &String, adj_list: &HashMap<String, HashSet<String>>, mut visited: HashSet<String>, small_revisited: bool) -> i32 {
+  let mut paths = 0;
+
+  if vertex.eq(&"end".to_string()) {
+    return 1;
+  }
+
+  if !is_upper_case(&vertex) {
+    visited.insert(vertex.clone());
+  }
+
+  let neighbours = &adj_list[vertex];
+
+  for neighbour in neighbours {
+    if neighbour.eq(&"start".to_string()) {
+      continue;
+    }
+
+    if !visited.contains(neighbour) {
+      paths += dfs_part_two(neighbour, adj_list, visited.clone(), small_revisited);
+    } else if !small_revisited {
+      paths += dfs_part_two(neighbour, adj_list, visited.clone(), true);
+    }
+    
+  }
+
+  return paths;
+}
+
+fn main() {
+  let mut start = Instant::now();
+
+  let mut adj_list: HashMap<String, HashSet<String>> = HashMap::new();  
+
+  let file_content = fs::read_to_string(INPUT_FILE).expect("File not found");
+  let line_regex = Regex::new(r"(\w+)-(\w+)").unwrap();
+
+  for capture in line_regex.captures_iter(&file_content) {
+    let left = (&capture[1]).to_string();
+    let left_copy = left.clone();
+    let right = (&capture[2]).to_string();
+    let right_copy = right.clone();
+
+    (*adj_list.entry(left).or_insert(HashSet::new())).insert(right_copy);
+    (*adj_list.entry(right).or_insert(HashSet::new())).insert(left_copy);
+  }
+
+  /*
+  for (vertex, egde_list) in (&adj_list).into_iter() {
+    println!("\"{:5}\": {:?}", &vertex, &egde_list);
+  }
+  */
+
+  println!("Parsing: {} ms", start.elapsed().as_millis());
+
+  start = Instant::now();
+  let p1_result = dfs_part_one(&"start".to_string(), &adj_list, HashSet::new());
+  println!("Part 1: {} in {} ms", p1_result, start.elapsed().as_millis());
+
+  start = Instant::now();
+  let p2_result = dfs_part_two(&"start".to_string(), &adj_list, HashSet::new(), false);
+  println!("Part 2: {} in {} ms", p2_result, start.elapsed().as_millis());
+}

README.md

@@ -2,9 +2,13 @@
 Done in variety of languages
 
 ### Progress
-![](https://img.shields.io/badge/day%20📅-14-blue)
-![](https://img.shields.io/badge/stars%20⭐-26-yellow)
-![](https://img.shields.io/badge/days%20completed-13-red)
+![](https://img.shields.io/badge/day%20📅-15-blue)
+![](https://img.shields.io/badge/stars%20⭐-28-yellow)
+![](https://img.shields.io/badge/days%20completed-14-red)
+
+### Notes
+* In all programs input file must be provided in the source code (usually somewhere at the top)
+* Additioal input that has to be provided in the code is stated in readme for given day
 
 ### Languages
 
@@ -21,7 +25,7 @@ Done in variety of languages
 |9|Processing||22||
 |10|Java||23||
 |11|C||24||
-|12|||25||
+|12|Rust||25||
 |13|Ruby|
 
 ![](https://i.redd.it/nx0xene4l1281.png)