Move Cafeteria code into new MultiInterval struct, add FromStr implementation for Interval

src/solvers/cafeteria.rs

@@ -1,74 +1,31 @@
-use crate::common::interval::Interval;
+use crate::common::interval::MultiInterval;
 use crate::solvers::Solver;
-use std::collections::BTreeSet;
 use std::io::BufRead;
 
 pub struct Cafeteria {}
 
-impl Cafeteria {
-    const INTERVAL_SPLIT_CHAR: char = '-';
-}
-
 impl Solver for Cafeteria {
     const PUZZLE_INDEX: u8 = 5;
     const PUZZLE_NAME: &'static str = "Cafeteria";
 
     fn process_data<R: BufRead>(&self, mut reader: R) -> (u64, u64) {
         // Builds intervals collection.
-        let mut intervals: BTreeSet<Interval> = BTreeSet::new();
+        let mut intervals = MultiInterval::new();
         for line in reader
             .by_ref()
             .lines()
             .map_while(|x| x.ok().filter(|s| !s.is_empty()))
         {
-            // TODO: This code should move into new common::interval::MultiInterval struct.
-            let values: Vec<u64> = line
-                .split(Self::INTERVAL_SPLIT_CHAR)
-                .map_while(|s| s.parse().ok())
-                .collect();
-            let mut interval = Interval::new(values[0], values[1]);
-
-            let mut to_delete = Vec::new();
-            for next in intervals.range(&interval..) {
-                if interval.contains(next.start) || interval.end + 1 == next.start {
-                    // New interval overlaps with the "next" interval already in the collection.
-                    if interval.end < next.end {
-                        interval.end = next.end;
-                    }
-                    to_delete.push(next.clone());
-                } else {
-                    break;
-                }
-            }
-
-            let mut do_insert = true;
-            if let Some(prev) = intervals.range(..=&interval).next_back() {
-                if interval.contains(prev.end) || prev.end + 1 == interval.start {
-                    // Enlarges new interval to replace the "previous" interval already in the collection.
-                    interval.start = prev.start;
-                    to_delete.push(prev.clone());
-                } else if interval.end <= prev.end {
-                    do_insert = false;
-                }
-            }
-
-            for del in to_delete {
-                intervals.remove(&del);
-            }
-
-            if do_insert {
-                intervals.insert(interval);
-            }
+            intervals.add(line.parse().unwrap());
         }
 
-        let mut part1 = 0;
         // Tests values against intervals.
-        for value in reader.lines().map_while(|x| x.ok()?.parse::<u64>().ok()) {
-            if intervals.iter().any(|interval| interval.contains(value)) {
-                part1 += 1;
-            }
-        }
+        let fresh_count = reader
+            .lines()
+            .map_while(|x| x.ok()?.parse::<u64>().ok())
+            .filter(|&value| intervals.contains(value))
+            .count() as u64;
 
-        (part1, intervals.iter().map(|x| x.len()).sum())
+        (fresh_count, intervals.len())
     }
 }