The Computer Language
Benchmarks Game

binary-trees Dart program

source code

/* The Computer Language Benchmarks game
   http://benchmarksgame.alioth.debian.org/

   contributed by Jos Hirth, transliterated from Jarkko Miettinen's Java program
*/

final int minDepth = 4;

void main(args){
  int n = args.length > 0 ? int.parse(args[0]) : 0;

  int maxDepth = (minDepth + 2 > n) ? minDepth + 2 : n;
  int stretchDepth = maxDepth + 1;

  int check = (TreeNode.bottomUpTree(0, stretchDepth)).itemCheck();
  print("stretch tree of depth $stretchDepth\t check: $check");

  TreeNode longLivedTree = TreeNode.bottomUpTree(0, maxDepth);

  for (int depth = minDepth; depth <= maxDepth; depth += 2){
    int iterations = 1 << (maxDepth - depth + minDepth);
    check = 0;

    for (int i = 1; i <= iterations; i++){
      check += (TreeNode.bottomUpTree(i, depth)).itemCheck();
      check += (TreeNode.bottomUpTree(-i, depth)).itemCheck();
    }
    print("${iterations * 2}\t trees of depth $depth\t check: $check");
  }
  print("long lived tree of depth $maxDepth\t check: ${longLivedTree.itemCheck()}");
}


class TreeNode{
  TreeNode left, right;
  int item;

  TreeNode(this.item, [this.left, this.right]);

  static TreeNode bottomUpTree(int item, int depth){
    if (depth > 0){
      return new TreeNode(
        item,
        bottomUpTree(2 * item - 1, depth - 1),
        bottomUpTree(2 * item, depth - 1)
      );
    }
    return new TreeNode(item);
  }

  int itemCheck(){
    if (left == null){
      return item;
    }
    return item + left.itemCheck() - right.itemCheck();
  }
}
    

notes, command-line, and program output

NOTES:
32-bit Ubuntu one core
Dart VM version: 1.20.1 (Wed Oct 12 15:01:12 2016) on "linux_ia32"



Wed, 19 Oct 2016 20:16:28 GMT

COMMAND LINE:
/usr/local/src/dart-sdk/bin/dart  binarytrees.dart 20

PROGRAM OUTPUT:
stretch tree of depth 21	 check: -1
2097152	 trees of depth 4	 check: -2097152
524288	 trees of depth 6	 check: -524288
131072	 trees of depth 8	 check: -131072
32768	 trees of depth 10	 check: -32768
8192	 trees of depth 12	 check: -8192
2048	 trees of depth 14	 check: -2048
512	 trees of depth 16	 check: -512
128	 trees of depth 18	 check: -128
32	 trees of depth 20	 check: -32
long lived tree of depth 20	 check: -1