PhoenixMomof2/selection-sort

algorithms and data structures

Day 4: Selection Sort

Learning Goals

• Practice algorithmic problem solving

Instructions

Sort an Array of numbers using selection sort. The selection sort algorithm sorts an array by repeatedly finding the minimum element (lowest value) in the input Array, and then putting it at the correct location in the sorted Array.

Input: [3, -1, 5, 2]
Output: [-1, 2, 3, 5]

You ARE allowed to use a built-in array method to find the minimum value—you need not recreate it algorithmically. Feel free to try it out for an extra challenge, though.

Use the language of your choosing. We've included starter files for some languages where you can pseudocode, explain your solution and code.

Benchmarking

For this task, we are also asking you to calculate the average runtime of your solution. In other words, you run it a bunch of times and then divide the total time it took for the solution to run by the number of times it ran.

Here is the pseudocode for creating your own basic benchmarking procedure:

store the current time in a variable called start time

loop 1000 times:
  execute the method using a small input, e.g. three items if input is an Array
  execute the method using a larger input, e.g. 100 items if input is an Array

average runtime = (current time - start time) / 2000

We have provided you with the long input to use for benchmarking.

Before you start coding

1. Rewrite the problem in your own words
2. Validate that you understand the problem
3. Write your own test cases
4. Pseudocode
5. Code!

And remember, don't run our tests until you've passed your own!

How to run your own tests

Ruby

1. cd into the ruby folder
2. ruby <filename>.rb

JavaScript

1. cd into the javascript folder
2. node <filename>.js

How to run our tests

Ruby

1. cd into the ruby folder
2. bundle install
3. rspec

JavaScript

1. cd into the javascript folder
2. npm i
3. npm test