Tree class with traverse Deep First and traverse Breadth First - Node.js Data Structure

Node.js examples for Data Structure:Tree

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Description

Tree class with traverse Deep First and traverse Breadth First

Demo Code


function findIndex(arr, data) {
  var index;//from  w w w . ja v  a2  s .  co  m
  for(var i = 0; i < arr.length; i++) {
    if(arr[i].data === data) {
      index = i;
    }
  }
  return index;
 }

/**
 * Node class
 **/
function Node(data) {
  this.children = [];
  this.parent = null;
  this.data = data;
}

/**
 * Tree constructor
 **/
function Tree(data) {
  var node = new Node(data);
  this._root = node;
}

Tree.prototype.traverseDF = function(callback) {
  (function recurse(currentNode) {
    for(var i = 0, length = currentNode.children.length; i < length; i++) {
      recurse(currentNode.children[i]);
    }
    callback(currentNode);
  })(this._root);
};

Tree.prototype.traverseBF = function(callback) {
  var queue = [];
  queue.push(this._root);
  var currentTree = queue.shift();
  while(currentTree) {
    for (var i = 0, length = currentTree.children.length; i <length; i++ ) {
      queue.push(currentTree.children[i]);
    }
    callback(currentTree);
    currentTree = queue.shift();
  };
};

Tree.prototype.contains = function(callback, travesral) {
  travesral.call(this, callback);
};

Tree.prototype.add = function(data, toData, traversal) {
  var child = new Node(data),
    parent = null,
    callback = function(node) {
      if(node.data ===  toData) {
        parent = node;
      }
    };

    this.contains(callback, traversal);

    if(parent) {
      parent.children.push(child);
      child.parent = parent;
    } else {
      throw new Error('Cannot add node to non-existing parent.')
    }
};

Tree.prototype.remove = function(data, fromData, traversal) {
  var tree = this,
    parent = null,
    childToRemove = null,
    index;

  var callback = function(node) {
    if(node.data === fromData) {
      parent = node;
    }
  };

  this.contains(callback, traversal);

  if(parent) {
    index = findIndex(parent.children, data);

    if(index === undefined) {
      throw new Error('Node to remove does not exist!');
    } else {
      childToRemove = parent.child.splice(index, 1);
    }
  } else {
    throw new Error('Parent does not exist!');
  }

  return childToRemove;
};

var tree = new Tree('one');

tree._root.children.push(new Node('two'));
tree._root.children[0].parent = tree;

tree._root.children.push(new Node('three'));
tree._root.children[1].parent = tree;

tree._root.children.push(new Node('four'));
tree._root.children[2].parent = tree;

tree._root.children[0].children.push(new Node('five'));
tree._root.children[0].children[0].parent = tree._root.children[0];

tree._root.children[0].children.push(new Node('six'));
tree._root.children[0].children[1].parent = tree._root.children[0];

tree._root.children[2].children.push(new Node('seven'));
tree._root.children[2].children[0].parent = tree._root.children[2];

console.log('***** DFS *****');
tree.traverseDF(function(node){
  console.log(node.data);
});

console.log('***** BFS *****');
tree.traverseBF(function(node){
  console.log(node.data);
});

console.log('***** Contains *****');

tree.contains(function(node) {
  if(node.data === 'h') {
    console.log(node);
  }
}, tree.traverseDF);

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