DEV Community

Cover image for Hackerrank's Algorithm: The Step
@Chrisdevcode
@Chrisdevcode

Posted on

Hackerrank's Algorithm: The Step

Introduction:

In this blog post, we'll delve into a simple yet powerful JavaScript function that generates beautiful staircase patterns. This pattern consists of rows and columns of characters, forming a visually appealing structure. By the end of this article, you'll have a clear understanding of how to create these patterns in your own JavaScript projects.

I notice how most devs find it difficult to pass this stage in the hacker rank's challenge, most of the articles about this online is either in another programming language or has the step inverted, and basically not how an actual step looks like.

Sample Out:

    #
   ##
  ###
 ####
#####
Enter fullscreen mode Exit fullscreen mode

Code Function:

Here's the code we'll be exploring:

function staircase(n) {
    for (let row = 0; row < n; row++) {
        let stair = '';

        for (let space = 0; space <= n - row - 2; space++) {
            stair += ' ';
        }

        for (let step = 0; step <= row; step++) {
            stair += '#';
        }
        console.log(stair);
    }
}
Enter fullscreen mode Exit fullscreen mode

The Goal:

The primary goal is to generate a staircase pattern with 'n' rows, each row containing spaces ' ', followed by characters '#' to emulate an actual staircase.

Code Walkthrough:

1. Function Declaration:

We begin by defining a JavaScript function named staircase which takes one argument, 'n'. This argument represents the number of rows in our staircase pattern.

2. Outer Loop (Row Iteration):

Inside the function, we have a 'for' loop with the variable 'row'. This loop controls the number of rows in our pattern. It starts at 0 and continues as long as 'row' is less than 'n'. In each iteration, we prepare a row.

3. Row Initialization:

Within each 'row' iteration, we initialize an empty string called 'stair' that will store the characters for the current row.

4. First Inner Loop (Space Calculation):

Now, we enter the first inner 'for' loop. Here, we have a variable 'space' that counts the number of spaces before the '#' characters in the current row. This loop runs while 'space' is less than or equal to 'n - row - 2'. The subtraction and iteration logic ensures that the number of spaces decreases from the top row to the bottom row.

5. Second Inner Loop (Adding '#'):

After calculating the spaces, we enter the second inner 'for' loop. This loop, with the variable 'step', adds '#' characters to the 'stair' string. It runs while 'step' is less than or equal to 'row'. This ensures that we add one '#' character for each row, creating a step-like structure.

6. Printing the Row:

Finally, we use console.log(stair) to print the 'stair' string, which represents the current row of the staircase.

Conclusion:

In summary, the 'staircase' function utilizes nested 'for' loops to construct a beautiful staircase pattern. The careful adjustment of spaces and '#' characters in each row results in a visually appealing output. By understanding this code, you can easily create similar patterns and explore more complex variations for your projects.

I hope with this little information, you're able to understand how to tackle the step algorithm. I'd encourage you to practice on your own free time and also try inverting the step as well.

Top comments (0)