Comment your Rust Code

Introduction

This post explains how to properly comment you Rust code.

Add Documentation to your Public APIs

/// This is a documentation comment

Documentation comments can be used to generate public HTML documentation. So these are ideal to document your public Structs, Methods and Functions. Also Documentation support markdown formats. Explain Panics, Errors, Examples of your code and whether your code is Safe or Unsafe.

Cargo runs your Doc Examples

To ensure your code is up to date, Cargo test will run examples in your documentation. This is really awesome.

Use Regular Comments for Code Internals

// This is a regular comment

Use regular comments to describe your code’s internals. These would not be included in the generated HTML file.

Machine Learning – a 10 minutes overview

What is Machine Learning

Vast number of programming problems can be solved by writing a set of well defined rules. Some problems are very complex it’s either we can’t define a clear set of rules or there are huge number of rules that it is impossible to manually codify those rules. A very good example is Speech recognition.

Machine Learning provides us technology so we can teach computers these rules provided a set of labeled data (training set) and extend them to a general set of data that were not seen in the training set.

Categories of Machine Learning

Supervised Learning

Goal of Supervised Learning is to predict the output variable from a given input variable. So for supervised learning, we need a data set with labeled output variables to train our machine learning function. If output variable is a category, it is Classification Problems. The functions we learn to solve these problems are called Classifiers. If output is a real value, it is a Regression Problem. Function we learn is called Regression Function.

Unsupervised Learning

Main goal here is to find some structure in a input data set. This involves,

Find clusters of similar data
Outlier detection

Machine Learning Workflow

Machine learning workflow mainly consists of three components.

Representation

This involves representing your problem in such a way that a computer can deal with it. So you have to extract a set of features from your input objects. Extraction most relevant set of features from your input objects is called Feature Extraction or Feature Engineering. Next part of the problem is choosing an appropriate machine learning methodology for the problem.

Evaluation

You need to have a framework to evaluate the accuracy of your ML algorithm. We usually set aside a set of test data for this.

Optimization

After evaluation step, you may find some improvements you could do. Such as choosing a more appropriate algorithm or extracting more relevant features.

Usually you have to iterate through above described steps before you can find an optimal solution for you problem.

How to Pass Google Phone Screen

Introduction

A few years ago, I managed to successfully pass the Google online coding test. It was extremely challenging. In this blog, I explain how I prepared for it.

Purpose of the Coding Test

The purpose of the online coding test is to identify candidates who may do well on the onsite interview. It basically measures how good problem solver, coder you are.

Exam / Test

You can use most of the popular programming languages (like Java, C++, Python, Ruby…). You will be talking to an interviewer throughout the test. Test usually last for about an hour. Given the time spend for introductions, coding part lasts for about 45 minutes.

Through out the exam you will be talking to an interviewer. Usually he would start with an simple coding question then add more and more complexity to it as you progress. You will be using google docs for coding.

Preparation

Brush up your knowledge on data structures and algorithms. Cover all basics.

Data Structures

Stack
LinkedList
Queue
Arrays
Heap
Binary Search Trees
Hashing

Algorithms

Sorts – Merge Sort, Quick Sort, Heap Sort, Topological Sort
Search – Binary Search
Tree Traversals – DFS, BFS, Inorder, PreOrder and Post Order

Do not waste your time looking at too complex data structures/algorithms. It is very unlikely you will get a complex problem given the time limitations.

Learn to Calculate Time / Memory Complexity

You are usually asked to provide the time/memory complexity of your code.So brush up how to calculate this on a code. Also try to remember time complexity of above classic algorithms.

Practice Practice Practice

The practice is the key. Do as much as practice questions you can. If you buy above book, you try the practice questions of the book. There are several online web sites like Leetcode which provide practice algorithmic questions. Make the best use of them.

During the Test

Don’t Rush In

Don’t jump into solving problem too quickly. Questions are bit ambiguous; this is on purpose. So discuss the problem, ask questions to clear out any ambiguities you may have.

Think Out Loud

Also keep a good communication with the interviewer. Speak out your thought process. If you can think of several solutions to solve the problem, discuss them with the interviewer. Tell him which is the best solution and why you think it is. Also, you can access the internet during the exam.

Write Good Code

This is the first time Google is going to see your code. So try to give the best first impression. Follow basics; use meaningful variable/method names, move the redundant code to functions. Try to create classes instead of using complex collections. Try to output the best industrial level software you can.

Do not Brute Force

You may be tempted to solve some problems by brute force. But this will not raise any eyebrows. Try to provide a code that can do better than the Brute Force.

Finally

Personally, I took about 3 weeks to prepare my self for the coding test. So start early.

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How to make a Blog Searchable in Google

How to make my WordPress blog searchable via Google? That was one of the first questions when I started my blog. Here is a very easy way to get it done without meta tags.

Step 1 – Go to Google Search Console

Follow this link

Step 2 – Add Property – add the Link of your web page

Click “Add Property” and add the link to your web page.

Step 3 – Verify the Ownership of your Webpage

Google asks you to verify the ownership of your page, this is where most of us run into problems.

Step 4 – Get DNS Verification Record

Click “Alternative Method” then select “Domain Name Provider”. You should see the following page.

You should add this record to your DNS.

Step 5 – Open WordPress Domains Page

Go to your WordPress Admin page. Go to Domain tab.

Step 6 – Then Select “Name Servers and DNS”

Step 7 – Then Click on “DNS Records”

Step 8 – Add Google Site Verification Code as a Record

Step 9 – Verify it on Google

DNS record instantly takes into effect. Go back to Google Search Console and click on Verify.

We are very responsive. Feel free to ask question/leave suggestions.

IELTS Tips

ielts

IELTS is a quite easy exam to pass, provided that you have prepared your self well for it. In this blog I am explaining what I did to ace the IELTS exam with less effort.

Step 1 – Find an Institution

There are several well-known institutions. Choose one which is conveniently located for you. It’s really a personal choice.

Watch out!!!

When you reserve the test, do not mention your real purpose of taking the test. They typically to set higher standards for people who take it for immigration reasons. There is no reason for IELTS institution to know why you are taking the exam. Just specify that you are taking the exam for a personal reason. If they compel you to give a reason, it’s best to go with a different institute.

Step 2 – Schedule a Test

Seriously, book your test, at the very beginning. Here are the reasons why should you do it.

There will be a long wait list. Typically 3 – 6 weeks
It will give the motivation to get committed to studying. It’s harder than you think to find time to study when there is no deadline

Know Your Exam

Check whether to take an Academic or a General exam. If you are doing this for a PR application, you should take the General module. For university applications, take the Academic exam.

Know How Much You Have to Score

Know how many points you need. This will help with time management.

Step 2 – Study

Personally, I spent 3-4 weeks preparing for the exam. IELTS exam comprises of 4 parts.

Reading

The exam takes about 50 minutes. You have to read a few articles and has to answer some questions. Cambridge University has a book with IELTS pass papers. Get a copy and do practice past papers. One trick I learned is to read the question once before you start reading the paragraphs. This really helps to save time.

It is very easy to waste lots of time here trying to perfecting your score. If all you need is a 7, why study for a 9. Save your effort/time for other areas.

Listening

During the exam, you will listen to some dialogs and answer some questions. Similar to Reading taking some pass papers should suffice. Don’t waste time perfecting your score.

Writing

During the exam, you will be asked to write one letter/memo and an essay. Do a few Cambridge pass papers. Find “IELTS Training modules by Adam Smith” for writing. Follow this module do some of its exercises.

Speaking

You will have to talk with an interviewer during the exam for about 15 minutes. First, you will have to speak a few minutes on a given topic, following a few minutes of general conversation on the same topic. Again follow IELTS module of Adam Smith provide which some great tips to get a high score for this exam.

Step 3 – Know How to Spend your Efforts

Here is how I spent my efforts during my IELTS preparation.

Reading – 15%

Listening – 15%

Writing – 45%

Speaking – 25%

Step 4 – Go for the Exam

Be there on time, bring your ID – the usuals.

We are very responsive. Feel free to ask question/leave suggestions.

How to Pass Google Phone Interview

Introduction

A few years ago, I managed to successfully pass the Google online coding test. It was extremely challenging. In this blog, I explain how I prepared for it.

Purpose of the Coding Test

The purpose of the online coding test is to identify candidates who may do well on the onsite interview. It basically measures how good problem solver, coder you are.

Exam / Test