Cracking the Coding Interview (CTCI) is widely regarded as a preeminent resource to prepare for modern software development position interviews at leading high tech companies.
The goal of this experience is to continue to get familiar with writing very simple Javascript code using JSFiddle, and to get you acquainted with the “Workout of the Day” (WOD) pedagogical technique used in this course.
To do this, you will solve the very first problem in CTCI, called “isUnique”:
1.1. Is Unique: Implement an algorithm to determine if a string has all unique characters.
For example:
console.log(isUnique('abcde')); // prints true
console.log(isUnique('abcdea')); // prints false
You should probably have finished the previous practice WOD.
Review the first few sections of the AirBnB Javascript Style Guide. For example, be sure to use let and const, not var.
Next, login to JSFiddle (creating an account if you haven’t already).
Check the settings pane to make sure the console window is displayed in the editor, and the layout is to your liking (I prefer “Tabs (rows)”).
To make the result window dark for your new JSFiddle, add the following to the CSS pane:
body { background-color: #1f2227; }
You may also want to reduce the height of the result window, so that more space is provided for the Javascript window.
For this practice WOD, implement a Javascript function called isUnique, which accepts a string and returns true if the string has all unique characters, false otherwise (i.e. if it contains any duplicates).
Ready? Let’s begin:
Start your timer.
Create a Javascript function called “isUnique”. The function should compute and return the answer. Print the results out to the console.
Informally test your program by running it and inspecting the output.
Press the “save” button to create a URL to refer to your code.
Stop your timer and record your time. Be sure to record the times associated with all of your attempts at this WOD, because you will need your WOD time data when you write your technical essay.
Rx: < 7 min Av: 7-10 min Sd: 10-12 min DNF: 12+ min
Once you’ve finished trying the WOD for the first time, watch me do it:
You’ll learn significantly less from watching me solve the WOD if you haven’t attempted the WOD yourself first.
While it’s an achievement to finish the WOD no matter how long it takes, you might experience “diminishing returns” if you work longer than the DNF time. Thus, it is usually strategic to stop working at the DNF time and watch my solution.
After watching my solution, I recommend that you repeat the WOD if you have not achieved at least Av performance. If so, be sure to:
Feel free to keep trying until you make Rx if that’s of interest to you.
By the time and date indicated on the Schedule page, submit this assignment via Laulima.
Your submission should contain:
A link to the JSFiddle created as a result of your latest attempt at this practice WOD. Make sure you include the complete URL so that I can click on it in my mailer.
The number of times you have attempted this practice WOD so far, and for each time, how long it took you.
You will receive full credit for this practice WOD as long as you have attempted it at least once and submitted your work on Laulima with all required data before the due date. Your code does not have to run perfectly for you to receive full credit. However, if you do not repeat each practice WOD until you can finish it successfully in at least AV time, you are unlikely to do well on the in-class WOD. To reduce the stress associated with this course, I recommend that you repeat each practice WOD as many times as necessary to achieve at least AV before its due date.