JavaScript Node #1 — Binary Trees

Style assessment

This is the canonical ES5 Benchmarks Game style: prototype-based TreeNode, recursive bottomUpTree/itemCheck, clear domain names (stretchDepth, longLivedTree), and idiomatic touches like +process.argv[2] and 1 << for the iteration count. Minor deductions for the dead unused `item` constructor parameter, var-based module-level script flow with no main function, and pre-ES6 syntax (const/let, class, template literals) that modern Node code would use.

/* The Computer Language Benchmarks Game
   http://benchmarksgame.alioth.debian.org/
   contributed by Isaac Gouy 
   *reset* 
*/

function TreeNode(left,right,item){
   this.left = left;
   this.right = right;
}

TreeNode.prototype.itemCheck = function(){
   if (this.left==null) return 1;
   else return 1 + this.left.itemCheck() + this.right.itemCheck();
}

function bottomUpTree(depth){
   if (depth>0){
      return new TreeNode(
          bottomUpTree(depth-1)
         ,bottomUpTree(depth-1)
      );
   }
   else {
      return new TreeNode(null,null);
   }
}


var minDepth = 4;
var n = +process.argv[2];
var maxDepth = Math.max(minDepth + 2, n);
var stretchDepth = maxDepth + 1;

var check = bottomUpTree(stretchDepth).itemCheck();
console.log("stretch tree of depth " + stretchDepth + "\t check: " + check);

var longLivedTree = bottomUpTree(maxDepth);
for (var depth=minDepth; depth<=maxDepth; depth+=2){
   var iterations = 1 << (maxDepth - depth + minDepth);

   check = 0;
   for (var i=1; i<=iterations; i++){
      check += bottomUpTree(depth).itemCheck();
   }
   console.log(iterations + "\t trees of depth " + depth + "\t check: " + check);
}

console.log("long lived tree of depth " + maxDepth + "\t check: " 
   + longLivedTree.itemCheck());