1 files changed, 57 insertions, 0 deletions
diff --git a/10/src/part-2.rs b/10/src/part-2.rs
new file mode 100644
index 0000000..76f8a2a
--- /dev/null
+++ b/10/src/part-2.rs
@@ -0,0 +1,57 @@
+use std::io::{BufRead};
+
+fn num(c: char) -> usize {
+    match c {
+        '(' => 0,
+        '[' => 1,
+        '{' => 2,
+        '<' => 3,
+        ')' => 4,
+        ']' => 5,
+        '}' => 6,
+        '>' => 7,
+        _   => panic!("Unknown character: {}", c)
+    }
+}
+
+pub fn main() {
+    let stdin = std::io::stdin();
+    let handle = stdin.lock();
+
+    let mut scores: Vec<usize> = Vec::new();
+    for l in handle.lines() {
+        let line = l.unwrap();
+        //println!("{}", line);
+        let mut corrupted = false;
+        let mut opened: Vec<usize> = Vec::new();
+        for c in line.chars() {
+            let i = num(c);
+            if i < 4 { // Open.
+                opened.push(i);
+            }
+            else { // Close.
+                let last_opened = opened.pop().unwrap_or(usize::MAX);
+                if i-4 == last_opened { // Valid
+                }
+                else { // Invalid.
+                    corrupted = true;
+                    break;
+                }                
+            }
+        }
+
+        if !corrupted {
+            //println!("Processing uncorrupted, incomplete line. Got {} opened.", opened.len());
+            scores.push(0);
+            for i in opened.into_iter().rev() {
+                let last_score: &mut usize = scores.last_mut().unwrap();
+                *last_score *= 5;
+                *last_score += i + 1;
+            }
+        }
+    }
+
+    scores.sort();
+    assert!(scores.len() % 2 == 1);
+    println!("Score: {}", scores[scores.len() / 2]);
+}