day 4

src/aoc04/mod.rs

@@ -0,0 +1,87 @@
+use std::error::Error;
+use std::fs;
+use std::collections::HashMap;
+use std::str;
+use regex::Regex;
+
+pub fn both(filename: &str) -> Result<(), Box<dyn Error>> {
+    let contents = fs::read_to_string(filename)?;
+
+    let mut valid_passports_simple = 0;
+    let mut valid_passports_extra = 0;
+    let mut passport: HashMap<&str, &str> = HashMap::new();
+    for line in contents.lines() {
+        if line.trim() == "" {
+            if passport.len() == 8 || (passport.len() == 7 && !passport.contains_key("cid")) {
+                valid_passports_simple += 1;
+                if validate_passport(passport) {
+                    valid_passports_extra += 1;
+                }
+            }
+            passport = HashMap::new();
+            continue
+        }
+
+        let entries = line.split(" ");
+        for entry in entries {
+            let kv: Vec<&str> = entry.split(":").collect();
+            passport.insert(kv[0], kv[1]);
+        }
+    }
+
+    println!("Valid Passports: {}", valid_passports_simple);
+    println!("Extra Valid Passports: {}", valid_passports_extra);
+
+    Ok(())
+}
+
+fn validate_passport(passport: HashMap<&str, &str>) -> bool {
+    let byr: u32 = passport.get("byr").unwrap().parse().unwrap();
+    if byr < 1920 || byr > 2002 {
+        return false
+    }
+
+    let iyr: u32 = passport.get("iyr").unwrap().parse().unwrap();
+    if iyr < 2010 || iyr > 2020 {
+        return false
+    }
+
+    let eyr: u32 = passport.get("eyr").unwrap().parse().unwrap();
+    if eyr < 2020 || eyr > 2030 {
+        return false
+    }
+
+    let hgt = passport.get("hgt").unwrap();
+    if hgt.ends_with("cm") {
+        let hval: u32 = hgt.split("cm").nth(0).unwrap().parse().unwrap();
+        if hval < 150 || hval > 193 {
+            return false
+        }
+    } else if hgt.ends_with("in") {
+        let hval: u32 = hgt.split("in").nth(0).unwrap().parse().unwrap();
+        if hval < 59 || hval > 76 {
+            return false
+        }
+    }  else {
+        return false
+    }
+
+    let hcl = passport.get("hcl").unwrap();
+    let hcl_re = Regex::new(r"\#[0-9a-f]{6}").unwrap();
+    if !hcl_re.is_match(hcl) {
+        return false
+    }
+
+    let ecl = passport.get("ecl").unwrap().trim();
+    if ecl.len() != 3 || !"amb blu brn gry grn hzl oth".contains(ecl) {
+        return false
+    }
+
+    let pid = passport.get("pid").unwrap();
+    let pid_re = Regex::new(r"^[0-9]{9}$").unwrap();
+    if !pid_re.is_match(pid) {
+        return false
+    }
+
+    true
+}

src/lib.rs

@@ -1,3 +1,4 @@
 pub mod aoc01;
 pub mod aoc02;
 pub mod aoc03;
+pub mod aoc04;

src/main.rs

@@ -10,6 +10,7 @@ fn main() {
         1 => advent_of_code::aoc01::both("./inputs/01-01.txt"),
         2 => advent_of_code::aoc02::both("./inputs/02-01.txt"),
         3 => advent_of_code::aoc03::both("./inputs/03-01.txt"),
+        4 => advent_of_code::aoc04::both("./inputs/04-01.txt"),
         _ => Err(format!("unsupported day {}", day).into()),
     };