Invert a Binary Tree

What makes this question special is this tweet. https://twitter.com/mxcl/status/608682016205344768?lang=en He questions the interview process, I am with him. But whatever it is, it is. Question : Invert a binary tree. Return the root of the inverted tree. 4 / \ 2 7 / \ / \ 1 3 6 9 to 4 / \ 7 2 … Continue reading Invert a Binary Tree

Advertisements

Data structures and algorithms practice resources

Data Structure and Algorithms resource guide.

bryanttunbutr

Here are the sites I have experience with and my thoughts

  • LeetCode is excellent because there are many problems and explanations. Furthermore the problems without explanations have answers and commented solutions in the discussion boards. It is the best online judge in my (limited) experience.
  • Code Wars is fun and great for learning a specific language and its features, i.e. JavaScript. But I did not find it as valuable for algorithms.
  • Cracking the Coding Interview has many questions and detailed answers in Java.
  • Data Structures and Algorithms Made Easy in Java is excellent. Sure there are many, many, many typos. But it has so many code samples for each of the data structures, explanations from worse (brute force) to best (optimized) along with advantages and disadvantages of the many possible solutions.

An honorable mention goes to Free Code Camp. The first time I ever had fun solving code challenges…

View original post 35 more words

Compare Versions

  Given two strings which represent different version releases of a software, print -1, 1 or 0 depending on the order of the releases. If version1 was released after version2 print 1, If version1 was released before version2 print -1, otherwise print 0. Assumptions granted : Strings may only contain digits and the '.'(dot) character … Continue reading Compare Versions

Step by step Kaggle competition tutorial

A clean and concise guide to Data Science.

Datanice

Kaggle is a Data Science community where thousands of Data Scientists compete to solve complex data problems.

In this article we are going to see how to go through a Kaggle competition step by step.

The contest explored here is the San Francisco Crime Classification contest. The goal is to classify a crime occurrence knowing the time and place it happened.

Screenshot from 2016-04-10 10:06:15.png

View original post 916 more words

3. Reverse Bits

Question : Write a program that takes a 64-bit word, output the reverse of that word. I would urge you to minimize the window and try to solve this question on your own first.   Method - 1 Brute Force Solution Simply apply the bitswap method we used earlier on all the extreme bits. Time … Continue reading 3. Reverse Bits

Standard Template Library : An Introduction

What is the Standard Template Library(STL) ? The Standard Template Library (STL) is a software library for the C++ programming language. It provides four components called containers, iterators, algorithms and functional. STL library lies in the std namespace. Why do we need to use the STL? 1. There is no use in inventing a wheel that has been in presence for … Continue reading Standard Template Library : An Introduction

Numbers and recipes at Codenmath.com

A much awaited day, a long lost dream, finally comes to life with codenmath.com, a wish I had for 9 years now; has awaken only to become a reality. At last a place where I can share all my knowledge, of whatever I have. A belly that has been so full of words will finally … Continue reading Numbers and recipes at Codenmath.com