How did you turn from a zero to a hero in programming?

I got rejected by one of my dream company because i was not able to answer few algorithms questions. I felt bad that time, and i immediately bought one monitor and started learning data structure and algorithms. Now i solve 3–4 problems everyday. I started few month back(1–2), i have reached to algorithms level 4, and percentile is 80+. So i think, you will not see your best unless you see your worst. That worked for me as an inspiration.

I had basic knowledge of data structure and algorithms that times. But you know if you don’t apply your knowledge to problems, you can’t achieve anything. I started with Cracking the coding interview book, used to solve warmup, implementation, string questions on hacker rank . We need to keep one thing in mind while learning. We don’t feel any difficulty in solving easy problems, but here we should look at others’ solution. And trust me these few approaches which you can learn with simple problems, will help you a lot in solving difficult problems in future. That was my strategy for learning competitive programming. As you move forward you will be able to write solution faster and with good time/space complexity.

I think you can not be pro at anything unless you love it. As a programmer love your job, love your work and be perfect at your work.

You should learn data structure and algorithms, it changes the way you write code or approach any problem.

For those who want to know about how to get started, i am listing resources which i used:

• There are many good books on algorithms, i would suggest Cracking the Coding Interview , CLRS .
• Start with hacker rank problems HackerRank (start with easy one)
• Top coder - Data Science Tutorials
• Interview Bit - Coding Interview Questions (you can even find questions for specific company here)
• Keep checking stack overflow data structure/ algorithms tag - Newest 'data-structures' Questions (You will find many new questions here, try to answer those, try to understand others’ answer.)
• Data Structures and Algorithms
• Problem Solving with Algorithms and Data Structures using Python
• Hackr.io - Find & share the best online programming courses & tutorials
• CMU algorithms wiki
• Learn about perfomance - Java Performance
• Learn about various concurrency models - Java Concurrency / Multithreading