Object Orientated Programming (OOP) is the approach to managing the flow of data within objects. Objects are data that we want to model from the world like for example a dog, phone, driver’s license, etc. The four main pillars for OOP are abstraction, encapsulation, inheritance, and polymorphism.

Abstraction is to…

“Given the `root`

of a binary tree, we will *check whether the binary tree is a mirror of itself* (i.e., symmetric around its center).”

-LeetCode

**Example 1:**

Problem 1: Second Highest Salary

The problem states:

“Write the SQL query from the Employee Table to compute the second highest salary”

`+----+--------+`

| Id | Salary |

+----+--------+

| 1 | 100 |

| 2 | 200 |

| 3 | 300 |

+----+--------+

In the case above we…

Solving this medium level leet code problem was frustrating to say the least. After learning how to solve such problem, I can explain how to approach such problem.

The problem: Given the *root** *of a binary tree, determine if it is a valid binary search tree (BST).

A valid binary…

Continuing on with building out the backend for our Picgram web app, I added the following to the Sessions Controller:

class SessionsController < Devise::SessionsController

# is where a user will authenticate his/her credentials and it will assign the JWT to the user if successful.

*def create user = User.find_by_email(sign_in_params[:email]) if…*

Some Flatiron School colleagues and myself decided to work on a group project in order to continue to flex our programming muscles! We decided to create a Instagram web application clone and add some features of d3.js, devise, Oauth and more in order to have more experience using these tools.

…

Problem 1: **Recursive Digit Sum**

We are given the task to solve for the super digit, which is the digit that is sum of a longer digit. Our known variables are *n *and *k*, *n *represents the large number that is a string and *k* represents the total amount of…

I’ve been learning much about D3 and its usefulness this past week. In the course so far I was able to do week 1 with no problem since it was just a JavaScript refresher course. For the week 2 curriculum, I learned about writing the code to create bar charts…

I came across D3 when I was applying to a position at a media company and was asked in a code challenge to submit a bar chart with data that is within a csv file. Unfortunately I was unable to complete the challenge but it opened my eyes to what…

This week I will be going over a problem from Hackerrank. The problem is titled Birthday Cake Candles.

1)Birthday Cake Candles

The problem reads:

You are in charge of the cake for a child’s birthday. You have decided the cake will have one candle for each year of their total…