From 1da99c63be8381b08ef8c7ebbc5bcc5899f21efc Mon Sep 17 00:00:00 2001
From: Daniel Seiller <earthnuker@gmail.com>
Date: Fri, 4 Dec 2020 14:58:01 +0100
Subject: [PATCH] Day 4

---
 src/day4.rs | 169 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/lib.rs  |   1 +
 2 files changed, 170 insertions(+)
 create mode 100644 src/day4.rs

diff --git a/src/day4.rs b/src/day4.rs
new file mode 100644
index 0000000..fbbb544
--- /dev/null
+++ b/src/day4.rs
@@ -0,0 +1,169 @@
+use aoc_runner_derive::{aoc, aoc_generator};
+use std::collections::HashMap;
+#[derive(Debug, PartialEq, Eq, Default)]
+pub struct Creds {
+    byr: Option<String>,
+    iyr: Option<String>,
+    eyr: Option<String>,
+    hgt: Option<String>,
+    hcl: Option<String>,
+    ecl: Option<String>,
+    pid: Option<String>,
+    cid: Option<String>,
+}
+
+impl Creds {
+    fn fields(&self) -> HashMap<&str, Option<String>> {
+        let mut ret = HashMap::new();
+        ret.insert("byr", self.byr.clone());
+        ret.insert("iyr", self.iyr.clone());
+        ret.insert("eyr", self.eyr.clone());
+        ret.insert("hgt", self.hgt.clone());
+        ret.insert("hcl", self.hcl.clone());
+        ret.insert("ecl", self.ecl.clone());
+        ret.insert("pid", self.pid.clone());
+        ret.insert("cid", self.cid.clone());
+        ret
+    }
+    fn is_valid_part1(&self) -> bool {
+        for (k, v) in self.fields() {
+            if k == "cid" {
+                continue;
+            }
+            if v.is_none() {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    fn year_in_range(val: &str, min: i64, max: i64) -> bool {
+        if val.len() != 4 {
+            return false;
+        }
+        if let Ok(val) = val.parse::<i64>() {
+            if val >= min && val <= max {
+                return true;
+            } else {
+                return false;
+            }
+        };
+        return false;
+    }
+
+    fn is_number(val: &str, ndigits: usize) -> bool {
+        val.chars().filter(|c| c.is_ascii_digit()).count() == ndigits
+    }
+
+    fn is_valid_height(val: &str) -> bool {
+        let it = val.chars();
+        let (num, unit): (String, String) = it.partition(|c| c.is_ascii_digit());
+        let num: Result<usize, _> = num.parse();
+        if let Ok(num) = num {
+            if unit == "cm" {
+                return num >= 150 && num <= 193;
+            };
+            if unit == "in" {
+                return num >= 59 && num <= 76;
+            };
+        }
+        return false;
+    }
+
+    fn validate_ecl(val: &str) -> bool {
+        let choices: Vec<&str> = vec!["amb", "blu", "brn", "gry", "grn", "hzl", "oth"];
+        return choices.iter().find(|&&v| v == val).is_some();
+    }
+
+    fn validate_hcl(val: &str) -> bool {
+        let mut ch = val.chars();
+        if ch.next() != Some('#') {
+            return false;
+        }
+        return ch.take_while(|v| v.is_ascii_hexdigit()).count() == 6;
+    }
+
+    fn validate(key: &str, value: &str) -> bool {
+        match key {
+            "byr" => Self::year_in_range(value, 1920, 2002),
+            "iyr" => Self::year_in_range(value, 2010, 2020),
+            "eyr" => Self::year_in_range(value, 2020, 2030),
+            "hgt" => Self::is_valid_height(value),
+            "pid" => Self::is_number(value, 9),
+            "ecl" => Self::validate_ecl(value),
+            "hcl" => Self::validate_hcl(value),
+            _ => false,
+        }
+    }
+
+    fn is_valid_part2(&self) -> bool {
+        for (k, v) in self.fields() {
+            if k == "cid" {
+                continue;
+            }
+            if let Some(v) = v {
+                if !Self::validate(k, &v) {
+                    return false;
+                }
+            } else {
+                return false;
+            }
+        }
+        return true;
+    }
+}
+
+#[aoc_generator(day4)]
+pub fn input_generator(input: &str) -> Vec<Creds> {
+    let mut ret = vec![];
+    for creds in input.split("\n\n") {
+        let creds = creds.replace("\n", " ");
+        let creds = creds.split(" ");
+        let mut cred_data = Creds::default();
+        for cred in creds {
+            let cred: Vec<&str> = cred.split(":").collect();
+            let (key, value) = (cred[0], cred[1]);
+            match key {
+                "byr" => {
+                    cred_data.byr = Some(value.to_string());
+                }
+                "iyr" => {
+                    cred_data.iyr = Some(value.to_string());
+                }
+                "eyr" => {
+                    cred_data.eyr = Some(value.to_string());
+                }
+                "hgt" => {
+                    cred_data.hgt = Some(value.to_string());
+                }
+                "hcl" => {
+                    cred_data.hcl = Some(value.to_string());
+                }
+                "ecl" => {
+                    cred_data.ecl = Some(value.to_string());
+                }
+                "pid" => {
+                    cred_data.pid = Some(value.to_string());
+                }
+                "cid" => {
+                    cred_data.cid = Some(value.to_string());
+                }
+                other => {
+                    panic!("Invalid key: {}", other);
+                }
+            }
+        }
+        ret.push(cred_data);
+    }
+    ret
+}
+
+#[aoc(day4, part1)]
+pub fn solve_part1(input: &Vec<Creds>) -> usize {
+    return input.iter().filter(|v| v.is_valid_part1()).count();
+}
+
+#[aoc(day4, part2)]
+pub fn solve_part2(input: &Vec<Creds>) -> usize {
+    return input.iter().filter(|v| v.is_valid_part2()).count();
+}
diff --git a/src/lib.rs b/src/lib.rs
index 19246c5..6da892d 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -2,4 +2,5 @@ use aoc_runner_derive::aoc_lib;
 pub mod day1;
 pub mod day2;
 pub mod day3;
+pub mod day4;
 aoc_lib! { year = 2020 }