Complete Day 4

lib/day4/command.dart

@@ -15,7 +15,7 @@ List getAdjacent(List<List<bool>> map, int idx, int idy) {
       //print("$xSlewed, $ySlewed");
       try {
         //print(map[ySlewed][xSlewed]);
-        adjacentValues.insert(adjacentValues.length, map[ySlewed][xSlewed]);
+        adjacentValues.add(map[ySlewed][xSlewed]);
       } on RangeError {
         continue;
       }
@@ -24,6 +24,30 @@ List getAdjacent(List<List<bool>> map, int idx, int idy) {
   return adjacentValues;
 }
 
+(int, List<List<bool>>) removeRolls(List<List<bool>> rollMap) {
+  int rollsRemoved = 0;
+  List<List<bool>> newRollMap = List.from(
+    rollMap.map((e) => List<bool>.from(e, growable: false)),
+    growable: false,
+  );
+  for (var (y, row) in rollMap.indexed) {
+    for (var (x, columnValue) in row.indexed) {
+      if (columnValue == true) {
+        var numAdjacent = getAdjacent(
+          rollMap,
+          x,
+          y,
+        ).where((value) => value).length;
+        if (numAdjacent < 4) {
+          rollsRemoved++;
+          newRollMap[y][x] = false;
+        }
+      }
+    }
+  }
+  return (rollsRemoved, newRollMap);
+}
+
 class Day4Command extends Command {
   // The [name] and [description] properties must be defined by every
   // subclass.
@@ -68,21 +92,18 @@ class Day4Command extends Command {
     //print(paperRollMap);
     //print(getAdjacent(paperRollMap, 0, 0));
 
-    int accumulator = 0;
-    for (var (y, row) in paperRollMap.indexed) {
-      for (var (x, columnValue) in row.indexed) {
-        if (columnValue == true) {
-          var numAdjacent = getAdjacent(
-            paperRollMap,
-            x,
-            y,
-          ).where((value) => value).length;
-          if (numAdjacent < 4) {
-            accumulator++;
+    int round = 1;
+    int totalRollsRemoved = 0;
+    while (true) {
+      int rollsRemoved;
+      (rollsRemoved, paperRollMap) = removeRolls(paperRollMap);
+      print("Rolls Removed During Round $round: $rollsRemoved");
+      if (rollsRemoved == 0) {
+        break;
       }
+      totalRollsRemoved += rollsRemoved;
+      round++;
     }
-      }
-    }
-    print("Part 1 Result: $accumulator");
+    print("Total Rolls Removed: $totalRollsRemoved");
   }
 }