[TASK] Finished Day 4

input/day4_example.txt

@@ -0,0 +1,13 @@
+ecl:gry pid:860033327 eyr:2020 hcl:#fffffd
+byr:1937 iyr:2017 cid:147 hgt:183cm
+
+iyr:2013 ecl:amb cid:350 eyr:2023 pid:028048884
+hcl:#cfa07d byr:1929
+
+hcl:#ae17e1 iyr:2013
+eyr:2024
+ecl:brn pid:760753108 byr:1931
+hgt:179cm
+
+hcl:#cfa07d eyr:2025 pid:166559648
+iyr:2011 ecl:brn hgt:59in

src/day4.rs

@@ -0,0 +1,68 @@
+// use super::util;
+use std::fs;
+
+static VALID_EYE_COLORS: &'static[&'static str] =
+    &["amb", "blu", "brn", "gry", "grn", "hzl", "oth"];
+
+pub fn solve() {
+    let raw_batch = fs::read_to_string("input/day4.txt").expect("Couldn't read file!");
+    let raw_fields = raw_batch
+        .split("\r\n\r\n")
+        .map(|s|
+            s.split(char::is_whitespace)
+                .filter(|s| !s.is_empty())
+                .map(|s| String::from(s))
+                .collect::<Vec<String>>()
+        ).collect::<Vec<Vec<String>>>();
+
+    let required_fields = ["byr:", "iyr:", "eyr:", "hgt:", "hcl:", "ecl:", "pid:"];
+    let valid_count1 =
+        raw_fields.iter().filter(|f|
+            required_fields.iter().all(|h|
+                f.iter().any(|s| s.starts_with(h)))
+        ).count();
+
+    println!("Day 4 Part 1: {}", valid_count1);
+
+    let valid_count2 = raw_fields.iter()
+        .filter(|rf| is_valid(rf))
+        .count();
+
+    println!("Day 4 Part 2: {}", valid_count2);
+
+}
+
+fn is_valid(fields: &Vec<String>) -> bool {
+
+    return fields.iter().any(|f| f.starts_with("byr:") && is_number_between(&f[4..], 1920, 2002))
+        && fields.iter().any(|f| f.starts_with("iyr:") && is_number_between(&f[4..], 2010, 2020))
+        && fields.iter().any(|f| f.starts_with("eyr:") && is_number_between(&f[4..], 2020, 2030))
+        && fields.iter().any(|f| f.starts_with("hgt:") && is_valid_height(&f[4..]))
+        && fields.iter().any(|f| f.starts_with("hcl") && is_valid_color(&f[4..]))
+        && fields.iter().any(|f| f.starts_with("ecl") && is_valid_eye_color(&f[4..]))
+        && fields.iter().any(|f| f.starts_with("pid") && is_digits(&f[4..]) && f[4..].len() == 9)
+    ;
+}
+
+fn is_number_between(s: &str, min: i32, max: i32) -> bool {
+    return str::parse::<i32>(s)
+        .map(|n| n >= min && n <= max).unwrap_or(false);
+}
+
+fn is_valid_height(s: &str) -> bool {
+    return (s.ends_with("cm") && is_number_between(&s[..(s.len() - 2)], 150, 193))
+        || (s.ends_with("in") && is_number_between(&s[..(s.len() - 2)], 59, 76));
+}
+
+fn is_valid_color(s: &str) -> bool {
+    return s.starts_with("#") &&
+        s[1..].chars().all(|c| (c >= '0' && c <= '9') || (c >= 'a' && c <= 'f'));
+}
+
+fn is_valid_eye_color(s: &str) -> bool {
+    return VALID_EYE_COLORS.contains(&s);
+}
+
+fn is_digits(s: &str) -> bool {
+    return s.chars().all(|c| c.is_ascii_digit());
+}

src/main.rs

@@ -5,6 +5,7 @@ mod util;
 mod day1;
 mod day2;
 mod day3;
+mod day4;
 
 fn main() {
 
@@ -18,6 +19,7 @@ fn main() {
             1 => day1::solve(),
             2 => day2::solve(),
             3 => day3::solve(),
+            4 => day4::solve(),
             _ => println!("This day is not yet implemented")
         }
     } else {
@@ -25,6 +27,7 @@ fn main() {
         day1::solve();
         day2::solve();
         day3::solve();
+        day4::solve();
     }
 
     println!("Execution took {} μs", now.elapsed().as_micros());