init day10.rs

src/day10.rs

@@ -1,16 +1,125 @@
+#![allow(dead_code)]
+
+use std::collections::{HashMap};
+
 type Stack = Vec<char>;
 
-fn part_1_solution() {
+fn part_1_solution(input: &str) -> u64 {
+    let point_table = HashMap::<char, u64>::from([
+        (')', 3),
+        (']', 57),
+        ('}', 1197),
+        ('>', 25137)
+    ]);
+
+    let match_table = HashMap::<char, char>::from([
+        (')', '('),
+        (']', '['),
+        ('}', '{'),
+        ('>', '<')
+    ]);
     
+    let mut count = 0;
+
+    for line in input.split_ascii_whitespace() {
+        let mut stack = Stack::new();
+        for c in line.chars() {
+            if "([{<".contains(c) {
+                stack.push(c);
+            } else {
+                let start = stack.pop().unwrap();
+                if start != *(match_table.get(&c).unwrap()) {
+                    count += point_table.get(&c).unwrap();
+                    break;
+                }
+            }
+        }
+    }
+
+    count
+}
+
+fn part_2_solution(input: &str) -> u64 {
+    let point_table = HashMap::<char, u64>::from([
+        (')', 1),
+        (']', 2),
+        ('}', 3),
+        ('>', 4)
+    ]);
+
+    let match_table_from_start = HashMap::<char, char>::from([
+        ('(', ')'),
+        ('[', ']'),
+        ('{', '}'),
+        ('<', '>')
+    ]);
+
+    let match_table_from_end = HashMap::<char, char>::from([
+        (')', '('),
+        (']', '['),
+        ('}', '{'),
+        ('>', '<')
+    ]);
+    
+    
+    let mut counts = vec![];
+
+    'outer:for line in input.split_ascii_whitespace() {
+        let mut stack = Stack::new();
+        for c in line.chars() {
+            if "([{<".contains(c) {
+                stack.push(c);
+            } else {
+                let start = stack.pop().unwrap();
+                println!("{} {}", start, c);
+                if start != *(match_table_from_end.get(&c).unwrap()) {
+                    continue 'outer;
+                }
+            }
+        }
+        let mut count = 0;
+        while !stack.is_empty() {
+            let c = stack.pop().unwrap();
+            count *= 5;
+            count += point_table.get(match_table_from_start.get(&c).unwrap()).unwrap();
+        }
+        counts.push(count);
+    }
+
+    counts.sort();
+    counts[counts.len() / 2]
 }
 
 #[cfg(test)]
 mod part1 {
     use super::*;
 
+    #[test]
+    fn run_sample() {
+        let input = include_str!("../inputs/10_test.txt");
+        assert_eq!(part_1_solution(input), 26397);
+    }
+
+    #[test]
+    fn run() {
+        let input = include_str!("../inputs/10.txt");
+        assert_eq!(part_1_solution(input), 339477);
+    }
+}
+
+#[cfg(test)]
+mod part2 {
+    use super::*;
 
     #[test]
     fn run_sample() {
-        part_1_solution()
+        let input = include_str!("../inputs/10_test.txt");
+        assert_eq!(part_2_solution(input), 288957);
+    }
+
+    #[test]
+    fn run() {
+        let input = include_str!("../inputs/10.txt");
+        assert_eq!(part_2_solution(input), 3049320156);
     }
 }