feat(08/2015): solve second part

Author: manhunto

readme.md

@@ -94,7 +94,7 @@
 | [Day 5: Doesn't He Have Intern-Elves For This?](src/solutions/year2015/day05.rs) |   ⭐⭐   |            0.261 |            0.987 |
 | [Day 6: Probably a Fire Hazard](src/solutions/year2015/day06.rs)                 |   ⭐⭐   |          871.538 |          817.533 |
 | [Day 7: Some Assembly Required](src/solutions/year2015/day07.rs)                 |   ⭐⭐   |            0.308 |            0.293 |
-| [Day 8: Matchsticks](src/solutions/year2015/day08.rs)                            |   ⭐    |            0.171 |                - |
+| [Day 8: Matchsticks](src/solutions/year2015/day08.rs)                            |   ⭐⭐   |            0.171 |            0.451 |
 
 # TODO
 

src/solutions/year2015/day08.rs

@@ -6,40 +6,67 @@ impl Solution for Day08 {
     fn part_one(&self, input: &str) -> String {
         input
             .lines()
-            .map(|l| {
-                let mut i: usize = 1;
-                let len = l.len();
-                let mut characters: usize = 0;
-
-                loop {
-                    if i == len - 1 {
-                        break;
-                    }
-
-                    if l.chars().nth(i).unwrap() == '\\' {
-                        if l.chars().nth(i + 1).unwrap() == 'x' {
-                            i += 3;
-                        } else {
-                            i += 1;
-                        }
-                    }
-
-                    characters += 1;
+            .map(|word| {
+                let result = Self::process(word);
 
-                    i += 1;
-                }
+                result.code_length - result.memory_length
+            })
+            .sum::<usize>()
+            .to_string()
+    }
 
-                len - characters
+    fn part_two(&self, input: &str) -> String {
+        input
+            .lines()
+            .map(|word| {
+                let encoded_string = format!("\"{}\"", word.escape_debug());
+
+                let original = Self::process(word);
+                let encoded = Self::process(&encoded_string);
+
+                encoded.code_length - original.code_length
             })
             .sum::<usize>()
             .to_string()
     }
+}
+
+impl Day08 {
+    fn process(word: &str) -> Result {
+        let mut i: usize = 1;
+        let len = word.len();
+        let mut memory: usize = 0;
 
-    fn part_two(&self, _input: &str) -> String {
-        String::from("0")
+        loop {
+            if i == len - 1 {
+                break;
+            }
+
+            if word.chars().nth(i).unwrap() == '\\' {
+                if word.chars().nth(i + 1).unwrap() == 'x' {
+                    i += 3;
+                } else {
+                    i += 1;
+                }
+            }
+
+            memory += 1;
+
+            i += 1;
+        }
+
+        Result {
+            code_length: len,
+            memory_length: memory,
+        }
     }
 }
 
+struct Result {
+    code_length: usize,
+    memory_length: usize,
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -51,4 +78,12 @@ mod tests {
         assert_eq!("3", Day08.part_one("\"aaa\\\"aaa\""));
         assert_eq!("5", Day08.part_one("\"\\x27\""));
     }
+
+    #[test]
+    fn part_two_example_test() {
+        assert_eq!("4", Day08.part_two("\"\""));
+        assert_eq!("4", Day08.part_two("\"abc\""));
+        assert_eq!("6", Day08.part_two("\"aaa\\\"aaa\""));
+        assert_eq!("5", Day08.part_two("\"\\x27\""));
+    }
 }