(rust) day 4 part 1 done

04/src/main.rs

@@ -55,7 +55,7 @@ fn group_shifts_by_guard(shifts: Vec<Shift>) -> HashMap<i32, Vec<Shift>> {
     return shifts_by_guard;
 }
 
-fn calculate_sleep(events: Vec<Event>) -> Vec<bool> {
+fn calculate_sleep(events: &Vec<Event>) -> Vec<bool> {
     let mut minutes = vec![false; 60];
     let mut sleeping = false;
     let mut last = 0;
@@ -74,6 +74,44 @@ fn calculate_sleep(events: Vec<Event>) -> Vec<bool> {
     return minutes;
 }
 
+fn count_awake_minutes(minutes: &Vec<bool>) -> i32 {
+    let mut sum = 0;
+    for minute in minutes {
+        if  *minute {
+            sum+=1;
+        }
+    }
+    return sum;
+}
+
+fn find_sleepy_guard(guards: &HashMap<i32, Vec<Shift>>) -> i32 {
+    let mut max_sleep = 0;
+    let mut id_of_sleepiest = -1;
+    for (guard, shifts) in guards {
+        let mut minutes_asleep = 0;
+        for shift in shifts {
+            minutes_asleep += count_awake_minutes(&calculate_sleep(&shift.events));
+        }
+        if minutes_asleep > max_sleep {
+            max_sleep = minutes_asleep;
+            id_of_sleepiest = guard.clone();
+        }
+    }
+    return id_of_sleepiest;
+}
+
+fn get_sleepy_minute(shifts: &Vec<Shift>) -> i32 {
+    let mut sleep_during_shifts = vec![0; 60];
+    for shift in shifts {
+        let minutes_asleep = calculate_sleep(&shift.events);
+        for i in 0..sleep_during_shifts.len() {
+            sleep_during_shifts[i] += if minutes_asleep[i] {1} else {0};
+        }
+    }
+    let sleepy_minute = sleep_during_shifts.iter().max().unwrap();
+    return sleep_during_shifts.iter().position(|&m| &m == sleepy_minute).unwrap() as i32;
+}
+
 fn main() {
     let lines: Vec<&str> = include_str!("../input").split("\n").collect();
     
@@ -93,5 +131,7 @@ fn main() {
     */
     let shifts_by_guard = group_shifts_by_guard(shifts);
     let sleepy_guard = find_sleepy_guard(&shifts_by_guard);
+    let sleepy_minute = get_sleepy_minute(&shifts_by_guard.get(&sleepy_guard).unwrap());
+    println!("guard {}, minute {}: {}", sleepy_guard, sleepy_minute, sleepy_guard * sleepy_minute);
 }