Now we have a lot of knowledge to put into practice. Even in the last blog post we talked about how to solve coding challenges. That post followed by the large amount of previous ones, you have the basis to solve current and next coding challenges. If you don’t know what’s our past blog post here you can see a list in order of each one of them

Articles about Ruby

* What's Ruby (Programming Language)?

* Ruby Data Types: Strings, Numbers and Booleans

* Variables and User Input in Ruby

* Control Flow and Conditionals in Ruby

* Ruby Times Loop and While Loop

* Ruby Each Loop

* Ruby Arrays

* Ruby Strings

* Ruby Hashes

* Ruby Functions

Articles about Data Structures

* Introduction to Ruby Data Structures and Complexity Analysis

* Relationship Between Memory and Data Structures

* Introduction to Big O Notation

* Introduction to Logarithms in Data Structures

* Framework to Solve Coding Challenges with Ruby

It’s important to have the basics of Ruby and Data Structures before doing coding challenges, because it can be hard if you don’t do that. All of the articles listed above are in order, which is important if you don’t know where to start or what’s the steps to follow to have all of these concepts

Write a function that takes in a non-empty array of integers that are sorted in ascending order and returns a new array of the same length with the squares of the original integers also sorted in ascending order. 

Pay attention to this problem, because it might seem very simple, however you have to take into account that while integers in the input array are sorted in increasing order, their squares won’t necessarily be as well, because of the possible presence of negative numbers. 

As you will see the expected results talk by themselves and can explain the expected behavior of your algorithm. When we see different inputs you have to return the output accordingly. 

Sample Input

Array = [1, 2, 3, 5, 6, 8, 9]

Sample Output

[1, 4, 9, 25, 36, 64, 81]

----------------------------------

Sample Input

Array = [1]

Sample Output

[1]

----------------------------------

Sample Input

Array = [-2, -1]

Sample Output

[4, 1] ⇒ Initial result, you have to sort it

[1, 4]

----------------------------------

Sample Input

Array = [-50, -13, -2, -1, 0, 0, 1, 1, 2, 3, 19, 20]

Sample Output

[2500, 169, 4, 1, 0, 0, 1, 1, 4, 3, 361, 400] ⇒ Initial result, you have to sort it

[0, 0, 1, 1, 1, 3, 4, 4, 169, 361, 400, 2500]

In one of our last blog posts we talñked about the framework to solve coding challenges, so now is the time to put that into practice. Remember the steps

Remember that there are always different ways to solve the same problem. So it is probably that you solved it with a different approach and that's ok, even that what matters: “you solve it”. Now let’s check this solution

def sorted_squared_array(array)

  ## O(n) time | O(n) space

  length = array.length - 1

  current_position = 0

  new_arr = []

  if array.length == 1

    p new_arr << array[current_position] ** 2

  else

    (1..length).each do |i|

      if array[current_position] <= array[i]

        p new_arr << array[current_position] ** 2

        current_position += 1

        if length == current_position

          p new_arr << array[current_position] ** 2

        end

      else

        return false

      end

    end

  end

  return new_arr.sort

end

p sorted_squared_array([1, 2, 3, 5, 6, 8, 9])

# p sorted_squared_array([1])

# p sorted_squared_array([1, 2])

# p sorted_squared_array([1, 2, 3, 4, 5])

# p sorted_squared_array([-2, -1])

# p sorted_squared_array([-5, -4, -3, -2, -1])

# p sorted_squared_array([0, 0, 0, 0, 0, 0, 0, 0, 0, 0])

# p sorted_squared_array([-1, -1, 2, 3, 3, 3, 4])

Is a good moment to congratulate yourself, you’ve solved your first coding challenge! 

You can start figuring out other kinds of solutions and that’s ok. 

I hope you learned a lot with this excescrise and let’s keep our progress

Thanks for reading

DanielM