(rust) day 4 WIP

04/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "d04"
+version = "0.1.0"
+authors = ["kageru <kageru@encode.moe>"]
+
+[dependencies]
+text_io = "0.1.7"
+

04/src/main.rs

@@ -0,0 +1,95 @@
+#[macro_use] extern crate text_io;
+use std::{fs, cmp};
+
+enum GuardAction {
+    shift_start(Guard),
+    shift_end(Guard),
+    fall_asleep,
+    wake_up,
+}
+
+struct Guard {
+    events: Vec<Event>,
+    id: i32,
+}
+
+#[derive(Eq)]
+struct DateTime {
+    month: i32,
+    day: i32,
+    hour: i32,
+    minute: i32,
+    sortable_time: i32,
+}
+    // Calculate the absolute minute count relative to 01/01 0:00. Months are assumed to have 31
+    // days because we just want to ensure that a higher month always results in a higher
+    // timestamp. Think of this as a primitive and less correct unix epoch.
+    pub fn get_sortable_time(month: i32, day: i32, hour: i32, minute: i32) -> i32 {
+        return minute + hour * 60 + day * 60 * 24 + month * 60 * 24 * 31;
+    }
+
+
+impl DateTime {
+    pub fn new(month: i32, day: i32, hour: i32, minute: i32) -> Self {
+        DateTime {
+            month,
+            day,
+            hour,
+            minute,
+            sortable_time: get_sortable_time(month, day, hour, minute)
+        }
+    }
+
+}
+
+impl Ord for DateTime {
+    fn cmp(&self, other: &DateTime) -> cmp::Ordering {
+        self.sortable_time.cmp(&other.sortable_time)
+    }
+}
+
+impl PartialOrd for DateTime {
+    fn partial_cmp(&self, other: &DateTime) -> Option<cmp::Ordering> {
+        Some(other.cmp(self))
+    }
+}
+
+impl PartialEq for DateTime {
+    fn eq(&self, other: &DateTime) -> bool {
+        self.sortable_time == other.sortable_time
+    }
+}
+
+struct Event {
+    datetime: DateTime,
+    action: GuardAction,
+}
+
+impl Event {
+    pub fn new(datetime: DateTime, action: GuardAction) -> Self {
+        Event {
+            datetime,
+            action
+        }
+    }
+}
+
+fn parse_action(input: &String) -> GuardAction {
+    return GuardAction::fall_asleep;
+}
+
+fn event_from_line(line: &String) -> Event {
+    let (month, day, hour, minute, unparsed_action): (i32, i32, i32, i32, String);
+    scan!(line.bytes() => "[1518-{}-{} {}:{}] {}", month, day, hour, minute, unparsed_action);
+    let datetime = DateTime::new(month, day, hour, minute);
+    return Event::new(datetime, parse_action(&unparsed_action));
+}
+
+fn main() {
+    let file = fs::read_to_string("../input").expect("can’t access file");
+    let lines: Vec<&str> = file.split("\n").collect();
+    let mut events: Vec<Event> = Vec::new();
+    for line in lines {
+        events.push(event_from_line(&line.to_string()));
+    }
+}