sarahzhao25

Security

Express Auth Gates Hiding secrets in Sequelize queries Protecting against Injection Hiding App Secrets

Authorization via Express Gates

Authentication == "who am i?"

sarahzhao25

Presentation Guide for Stackathon

Individual Presentation (No more than 5 minutes!)

Your Vision

Introduce what the project is, the story behind it and what interested in you the project.

User Story

If you have something to present, walk everyone through a user story of your app. Or if you don't have a user story, you can walk through the working parts of your app. Or if you really don't have much to show, a slide deck of a few slides of what you were trying to would suffice.

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K-Messed Array Sort

See Repl

Prompt

Given an array of integers arr where each element is at most k places away from its sorted position, write a function sortKMessedArray that sorts arr.

Example

For an input array of size 10 and k = 2, an element belonging to index 6 in the sorted array will be located at either index 4, 5, 6, 7 or 8 in the input array.

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NOTE: This was taken from Cracking the Coding Interview 6th Edition.

Prompt

You have two numbers represented by a linked list, where each node contains a single digit. The digits are stored in reverse order, such that the 1's digit is at the head of the list. Write a function that adds the two numbers and returns the sum as a linked list.

Example

Input: (7 -> 1 -> 6) + (5 -> 9 -> 2). That is, 617 + 295. Output: (2 -> 1 -> 9). That is, 912.

Solution

sarahzhao25

//ROOT Tree (rotated to RIGHT):
{
  this.value = 15;
  this.left = null;
  this.right = null;
  this.parent = {node: BST(10), side: 'right'};
}
//root.height() => 0;
//root.balanceFactor() => 0;

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//ROOT Tree:
{
  this.value = 15;
  this.left = BST(10);
  this.right = null;
  this.parent = {node: BST(20), side: 'left'};
}
//root.height() => 2;
//root.balanceFactor() => 2;

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BinarySearchTree.prototype.balanceFactor = function() {
  return this.height(this.left) - this.height(this.right);
}

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function BinarySearchTree(value) {
  this.value = value;
  this.left = this.right = null;
  this.parent = {node: null, side: ‘’};
}

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function rightRotate(root) {
  let pivot = root.left;
  if (pivot.right) {
    //establish right to be child of root's parent.
    pivot.right.parent.node = root;
    pivot.right.parent.side = 'left';
  }
  root.left = pivot.right;
  pivot.parent.node = root.parent.node;
  (root.parent.node) ? root.parent.node[root.parent.side] = pivot: pivot.parent.side = '';

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function rotate(root) {
  if (root.balanceFactor() > 1) {
    if (root.left.balanceFactor() === -1) leftRotate(root.left);
    rightRotate(root);
  }
  else if (root.balanceFactor() < -1) {
    if (root.right.balanceFactor() === 1) rightRotate(root.right);
    leftRotate(root);
  }
 }