Hello, fellows!
Solving coding challenges will benefit you not just in the interview process, but also in your day-to-day life as a developer.
So, in this article, I'll walk you through several steps you can take to approach coding problems, and then I'll show you some practical CodeWars examples.
Let’s dive in. 🏊♀️
1. Understand the problem 💭
We have a natural tendency to rush through activities, including problem solving. We begin attacking a problem without even knowing what we are trying to solve.
As a first step, try to read the problem carefully, ask yourself questions, simplify data, and only then begin to solve it.
Helpful questions: What do I know? What data is available? What should be the end result?
2. Make a strategy 📝
After I am sure that I have understood the problem, I usually formulate a plan, even writing down some step-by-step thoughts on how to address the problem.
Write your ideas in pseudocode.
3. Solve the problem 💡
The following step is to address the problem itself.
Of course, you may be tempted to seek easier solutions from others, but I encourage you to solve the problem as best you can. Don't get focused on the difficult parts; instead, concentrate on what can be done. Perhaps, in time, your mind will come up with some brilliant solutions to the difficult parts!
You can do it! 😄
4. Optimize the code 🗖
After you've solved the problem and it's working successfully, you might spend some time improving and refactoring it to make it more effective.
Here’s how I solved a CodeWars problem with JavaScript using these steps:
Moving Zeros To The End
The problem description:
Write an algorithm that takes an array and moves all of the zeros to the end, preserving the order of the other elements.
moveZeros([false,1,0,1,2,0,1,3,"a"]) // returns[false,1,1,2,1,3,"a",0,0]
1.What do I know and what are the inputs? What should be the end result?
I have an array as input and should return an array with all zeros moved to the end. The order of the other elements must also be maintained.
Here is a simplified example based on this problem:
moveZeros([2, 0, 5, 0, “a”]) // returns [2, 5, “a”, 0, 0]
2.Pseudocode
My first mechanical approach was to divide two arrays in order to keep order and separate from zeros:
Initialize array1 to empty array
Initialize an array for zeros to empty array
For each element in the input array
If the element equals 0
Push the 0 into array of zeros
Else
Push the element into array1
Return concatenated array1 with array of zeros
3.Solving the problem:
var moveZeros = function (arr) {
let array1 = [];
let arrayOfZeros = [];
for (let i = 0; i < arr.length; i++) {
if (arr[i] === 0) {
arrayOfZeros.push(arr[i]);
} else {
array1.push(arr[i]);
}
}
return [...array1,...arrayOfZeros];
}
4.Optimizing the solution:
I was thinking about filtering elements as a way to improve the solution. Filtering elements with values other than zero and elements with values equal to zero.
filter in JavaScript returns a new array containing filtered elements.
Finally, the optimized solution is as follows:
var moveZeros = function (arr) {
return [...arr.filter(value => value !== 0),...arr.filter(value => value === 0)];
}
We can also use concat method in order to concatenate the filtered arrays:
var moveZeros = function (arr) {
return arr.filter(value => value !== 0).concat(arr.filter(value => value === 0));
}
Final thoughts
I hope this helps you overcome difficulties as a developer, whether in technical interviews or on a daily basis.
To begin, you may look for a better solution to the problem I discussed before. 😊
Last but not least, practicing problem solving with patience may lead to you becoming a better and faster problem solver. 💨💨💨
Keep up the good work until the next time! 🎉