Complete day 5

lib/day5/command.dart

@@ -1,8 +1,87 @@
 import "dart:convert";
 import "dart:io";
+import "dart:math";
 
 import "package:args/command_runner.dart";
 
+class Range implements Comparable<Range> {
+  // The start and end of this range
+  final int start;
+  final int end;
+
+  Range(this.start, this.end);
+
+  @override
+  String toString() {
+    return "[$start..$end]";
+  }
+
+  bool inRangeInclusive(int value) {
+    return start <= value && value <= end;
+  }
+
+  int length() {
+    return end - start + 1;
+  }
+
+  /// Ordered by start and then by end
+  @override
+  int compareTo(Range other) {
+    int startCompare = start.compareTo(other.start);
+    if (startCompare == 0) {
+      return end.compareTo(other.end);
+    }
+    return startCompare;
+  }
+}
+
+class RangeSet {
+  final List<Range> ranges;
+
+  RangeSet._internal(this.ranges);
+
+  factory RangeSet(Iterable<Range> ranges) {
+    // Create and sort ranges list
+    List<Range> rangesList = List.from(ranges, growable: false);
+    rangesList.sort();
+
+    // Combine and compact adjacent ranges
+    List<Range> compactedList = [rangesList[0]];
+    for (Range range in rangesList.sublist(1)) {
+      Range lastRange = compactedList.last;
+      if (range.start <= lastRange.end) {
+        compactedList[compactedList.length - 1] = Range(
+          lastRange.start,
+          max(lastRange.end, range.end),
+        );
+      } else {
+        compactedList.add(range);
+      }
+    }
+    return RangeSet._internal(compactedList);
+  }
+
+  @override
+  String toString() {
+    return ranges.toString();
+  }
+
+  Range operator [](int index) => ranges[index];
+
+  bool inRangeSetInclusive(int value) {
+    for (var range in ranges) {
+      if (range.inRangeInclusive(value)) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  int length() {
+    return ranges.map((r) => r.length()).reduce((left, right) => left + right);
+  }
+}
+
 class Day5Command extends Command {
   // The [name] and [description] properties must be defined by every
   // subclass.
@@ -33,13 +112,41 @@ class Day5Command extends Command {
 
     print("Parsing file: $filePath");
     var inputFile = File(filePath);
-    var result = await inputFile
+    var listOfRanges = inputFile
         .openRead()
         .transform(utf8.decoder)
         .transform(LineSplitter())
+        .takeWhile((line) => line.isNotEmpty)
         .map((line) {
-          return line;
+          var splitLine = line.split("-");
+          return Range(int.parse(splitLine[0]), int.parse(splitLine[1]));
         })
         .toList();
+
+    List<int> listOfIds = await inputFile
+        .openRead()
+        .transform(utf8.decoder)
+        .transform(LineSplitter())
+        .skipWhile((line) => line.isNotEmpty)
+        .skipWhile((line) => line.isEmpty)
+        .map((line) {
+          return int.parse(line);
+        })
+        .toList();
+    RangeSet freshIdRanges = RangeSet(await listOfRanges);
+
+    //print(freshIdRanges);
+    //print(listOfIds);
+
+    int freshCount = 0;
+
+    for (int id in listOfIds) {
+      if (freshIdRanges.inRangeSetInclusive(id)) {
+        freshCount++;
+      }
+    }
+
+    print("Fresh IDs: $freshCount");
+    print("Total ingredient ids considered fresh: ${freshIdRanges.length()}");
   }
 }