Whiteboard testing is the savior

Oct. 26, 2017

Introduction

It is the best decision to practice mock interview starting from today. As usual, I choose to practice 10:00 PM since it is too late to work and usually I am so tired, usually I have difficult time to think clearly after long day, I like to drill myself to simulate tough situation at work. My last practice is Sept. 27, 2017. Since I took a vacation from Oct. 5 to Oct. 20, I did not practice mock interview at all.

Today I spent first 15 minutes to write code, and then I relied on my techniques using Terse, Express the intent, Do one thing (TED) principle, and then I made the change to look ahead to determine if it is ready to compare (line 33: readyToCompare), I passed all test cases in the 35th minute.

In summary, the algorithm I had to write is a linear scan algorithm, instead of looking ahead to determine if it is the last row in the current time stamp, first 25 minutes I worked on the idea to look backward to compare to previous time. Once I play with whiteboard testing, I figure out the solution 100% correctly.

Code review

C# code is here. Plan to highlight a few changes I made.

Line 29 - comment out line 29, the peer reminded me no need to use startNewTime, previousTimeStamp

Line 40 - max = sum;  // the peer reminded me that sum is the new max value.

Actionable Item

Usually linear scan algorithm I should aim at 10 minutes to perform.