My Experience With a Programmer Coding Test (Survey)(spreadsheets.google.com)

  Array.prototype.contains = function(obj) {
    // copied from http://stackoverflow.com/questions/237104/javascript-array-containsobj
    var i = this.length;
    while (i--) {
      if (this[i] === obj) {
        return true;
      }
    }
    return false;
  }
  
  function doTree (node, func) {
    var seen = [];
    var to_see = [node];
    while to_see.length {
      var next_node = to_see.pop();
      func(next_node.value);
      seen.push(next_node);
      for (var i; i < next_node.children.length; i++) {
        var child = next_node.children[i];
        if (! seen.contains(child) && ! to_see.contains(child)) {
          to_see.push(child);
        }
      }
    }  
  }
  
  // --
  
  var num_arr = [];
  var sum = 0;
  doTree(numTree, function (val) { num_arr.push(val); })
  // googled for a sum function. didn't know if javascript had map or reduce in stdlib.
  
  for (var i; num_arr.length; i++) {
    sum += num_arr[i];
  }
  
  // sum is sum.

  do_tree([Value | Children], Fun) ->
    [Fun(Value) | [do_tree(Child, Fun) || Child <- Children]];
  do_tree([], _Fun) -> [].

  sum_tree(NumTree) ->
    lists:foldl(fun(Elem, AccIn) -> Elem+AccIn end, 0,
      lists:flatten(do_tree(NumTree, fun(Value) -> Value end))).

  function doTree(node, fn) {
       fn(node.value);
       for (var i = 0; i < node.children.length; ++i) {
           doTree(node.children[i], fn);
       }
   }

  var sum = 0;
  doTree(numTree, function(value) { sum += value; });