binarySearchTree.js

/*-----------------------------------------------------------------------------
the reference is from UdemyCourse: LearningDataStructuresinJavascriptFromScratch
-----------------------------------------------------------------------------*/
function BST(value) {
  this.value = value;
  this.left = null;
  this.right = null;
}


BTS.prototype.insert = function(value){
  if(value <= this.value) {
    if(!this.left) {
      this.left = new BST(value);
    }
    else {
      this.left.insert(value);
    }
  }
  else if (value > this.value) {
    if(!this.right){
      this.right = new BST(value);
    }
    else {
      this.right.insert(value);
    }
  }
};


BST.prototype.contains = function(value){
  if(value === this.value) {
    return true;
  }
  else if (value < this.value) {
    if(!this.left) return false;
    else return this.left.contains(value);
  }
  else if (value > this.value) {
    if(!this.right) return false;
    else return this.right.contains(value);
  }
};


BST.prototype.depthFirstTraversal = function(iteratorFunc, order){
  
  // root left right
  if(order === 'pre-order') iteratorFunc(this.function);
  
  if(this.left) this.left.depthFirstTraversal(iteratorFunc, order);
  
  // left root right
  if(order === "in-order") iteratorFunc(this.value);
  
  if(this.right) this.right.depthFirstTraversal(iteratorFunc, order);
  
  // left right root
  if(order === 'post-order') iteratorFunc(this.value);
  
};


BST.prototype.BreadthFirstTraversal = function(iteratorFunc) {
  var queue = [this];

  while (queue.length) {
    var treeNode = queue.shift();
    iteratorFunc(treeNode);
    
    if(treeNode.left) queue.push(treeNode.left);
    
    if(treeNode.right) queue.push(treeNode.right); 
    
  }
};


function log(value) {
  console.log(value);
}


BST.prototype.getMinVal = function () {
  if(this.left) return this.left.getMinVal();
  else return this.value;
};


BST.prototype.getMaxVal = function () {
  if(this.right) return this.right.getMaxVal();
  else return this.value;
};



var bst = new BST(2);
bst.insert(31);
bst.insert(311);
bst.insert(21);
bst.insert(45);
bst.insert(98);
bst.insert(1);

bst.depthFirstTraversal(log, 'post-order');

Pseudo code here
https://medium.freecodecamp.org/deep-dive-into-graph-traversals-227a90c6a261

DFS traversal
https://medium.com/basecs/deep-dive-through-a-graph-dfs-traversal-8177df5d0f13