y2015d8

y2015/src/bin/d8.rs

@@ -0,0 +1,20 @@
+use std::fs;
+
+use y2015::days::d8;
+
+fn main() {
+    part1();
+    part2();
+}
+
+fn part1() {
+    let root = env!("CARGO_MANIFEST_DIR");
+    let content = fs::read_to_string(format!("{root}/resources/8_input.txt")).unwrap();
+    println!("{}", d8::process_part1(&content));
+}
+
+fn part2() {
+    let root = env!("CARGO_MANIFEST_DIR");
+    let content = fs::read_to_string(format!("{root}/resources/8_input.txt")).unwrap();
+    println!("{}", d8::process_part2(&content));
+}

y2015/src/days/d8.rs

@@ -0,0 +1,64 @@
+pub fn process_part1(input: &str) -> u32 {
+    let slashed_quote = r#"\""#;
+    let double_slash = r#"\\"#;
+    let escape = r#"\x"#;
+
+    let num_char_string_code: u32 = input.lines().map(|line| line.len() as u32).sum();
+    let num_char_mem: u32 = input
+        .lines()
+        .map(|line| {
+            // first remove \\ and \" and replace with single random character so they count for
+            // one instead of 2
+            let line = line.to_string();
+            let line = line.replace(double_slash, "x");
+            let line = line.replace(slashed_quote, "x");
+            // only count what's in the quotes
+            let inner_quote_length = line.len() - 2;
+            let num_ascii_codes = line.matches(escape).count() * 3;
+            (inner_quote_length - num_ascii_codes) as u32
+        })
+        .sum();
+    num_char_string_code - num_char_mem
+}
+
+pub fn process_part2(input: &str) -> u32 {
+    let slashed_quote = r#"\""#;
+    let double_slash = r#"\\"#;
+    let escape = r#"\x"#;
+
+    let num_char_string_code: u32 = input.lines().map(|line| line.len() as u32).sum();
+    let num_char_encode: u32 = input
+        .lines()
+        .map(|line| {
+            let line = line.to_string();
+            let line = line.replace(double_slash, "xxxx");
+            let line = line.replace(slashed_quote, "xxxx");
+            let line = line.replace(escape, "xxx");
+            line.len() as u32 + 4
+        })
+        .sum();
+    num_char_encode - num_char_string_code
+}
+
+#[cfg(test)]
+mod tests_8 {
+    use super::*;
+
+    const INPUT: &str = r#"""
+"abc"
+"aaa\"aaa"
+"\x27"
+"#;
+
+    #[test]
+    fn it_works() {
+        let result = process_part1(INPUT);
+        assert_eq!(result, 12);
+    }
+
+    #[test]
+    fn part2() {
+        let result = process_part2(INPUT);
+        assert_eq!(result, 19);
+    }
+}

y2015/src/days/mod.rs

@@ -5,3 +5,4 @@ pub mod d4;
 pub mod d5;
 pub mod d6;
 pub mod d7;
+pub mod d8;