Added Day 4 Part 2

src/main.rs

@@ -38,9 +38,51 @@ fn main() {
 }
 
 fn validate(map: &HashMap<String, String>, key: &str) -> bool {
-    if let Some(v) = map.get(key) {
-        !v.is_empty()
-    } else {
-        false
+    match (key, map.get(key)) {
+        ("byr", Some(v)) => {
+            let byr = v.parse::<i32>().unwrap();
+            byr >= 1920 && byr <= 2002
+        }
+        ("iyr", Some(v)) => {
+            let iyr = v.parse::<i32>().unwrap();
+            iyr >= 2010 && iyr <= 2020
+        }
+        ("eyr", Some(v)) => {
+            let eyr = v.parse::<i32>().unwrap();
+            eyr >= 2020 && eyr <= 2030
+        }
+        ("hgt", Some(v)) => {
+            if v.contains("cm") {
+                let v = v.trim_end_matches(char::is_alphabetic);
+                let v = v.parse::<i32>().unwrap();
+                v >= 150 && v <= 193
+            } else if v.contains("in") {
+                let v = v.trim_end_matches(char::is_alphabetic);
+                let v = v.parse::<i32>().unwrap();
+                v >= 59 && v <= 76
+            } else {
+                false
+            }
+        }
+        ("hcl", Some(v)) => {
+            v.starts_with('#')
+                && v.chars()
+                    .skip(1)
+                    .filter(|x| match x {
+                        '0'..='9' => true,
+                        'a'..='f' => true,
+                        _ => false,
+                    })
+                    .count()
+                    == 6
+        }
+        ("ecl", Some(v)) => match v.as_ref() {
+            "amb" | "blu" | "brn" | "gry" | "grn" | "hzl" | "oth" => true,
+            _ => false,
+        },
+        ("pid", Some(v)) => v.len() == 9 && v.chars().filter(|&x| char::is_numeric(x)).count() == 9,
+        ("cid", _) => true,
+        (_, None) => false,
+        (_, _) => unreachable!(),
     }
 }