JS Exercises

This project can be used to experiment with basic algorithms implemented in JavaScript.

Installation

1. Clone the repository in your local environment.
2. Run npm install
3. Run npm test
4. If you are in the master branch, all tests will fail, because the code is not implemented yet.

How to use this project

NOTE: Please do not commit to master

1. Create a new branch with the suggested structure {github_account_name}-solution (e.g: bcisneros-solution).
2. Choose the exercise you want to resolve and run the corresponding tests (e.g npm run test:fizzbuzz)
3. Read the description and modify the code to pass all rules.
4. Format your code using VS Code Prettier extension or running npm run format
5. Check the code has no Linter errors with npm run lint
6. Push your branch to Github: git push -u origin {your_branch}

Exercises

FizzBuzz

Given an integer number, return:

• "Fizz" if the number is divisible by 3
• "Buzz" if the number is divisible by 5
• "FizzBuzz" if the number is divisible by 3 and 5
• the number as string in any other case.

Files: src/fizzbuzz.js and tests/fizzbuzz.test.js

Hello

Write a function with the name hello that receives a string that represents a person's name and returns another string that represents a greeting to that person, with the following rules:

• For single names return "Hello {name}!"
  • hello("John") returns "Hello John!"
  • hello("Susan") returns "Hello Susan!"
• If name is Robert, Katherine, or Garfield, return "Hello {nickname}!"
  • hello("Robert") returns "Hello Bob!"
  • hello("Katherine") returns "Hello Katy!"
  • hello("Garfield") returns "Hello Mr. G!"
• If the name has a length of 10 or more letters, return only the first 3 letters
  • hello("Maximiliano") returns "Hello Max!"
  • hello("Evangeline") returns "Hello Eva!"
• Names are capitalized, regardless if they come in any combination of lower and upper cases:
  • hello("ariana") returns "Hello Ariana!"
  • hello("CESAR") returns "Hello Cesar!"
  • hello("OrlANDo") returns "Hello Orlando!"
  • hello("robert") returns "Hello Bob!" because the nickname rule
• If the name is an empty string, contains only blank spaces, is null or undefined, returns "Hello Anonymous!"

Roman Numbers

• asRoman(decimal): Converts a decimal number to its Roman Numeral representation.
• asDecimal(roman): Converts a string Roman Numeral representation to decimal

Reference: https://en.wikipedia.org/wiki/Roman_numerals

Files: src/roman_numbers.js and tests/roman_numbers.test.js

English number names

Given an integer number, return its name in English.

Reference: https://en.wikipedia.org/wiki/English_numerals

Files: src/english_number_names.js and tests/english_number_names.test.js

Array product exclusion

Given an array of integers, return an array of integers such that the value at index i of the output is the product of everything in the input except the input value at index i. An empty list should return []. A list of length 1 should return [1] no matter the input element.

Example:

productExclusion([]) => [];
productExclusion([2]) => [1];
productExclusion([3]) => [1];
productExclusion([1, 2]) => [2, 1];
productExclusion([1, 2, 3]) => [6, 3, 2];
productExclusion([2, 3, 4, 5]) => [60, 40, 30, 24];

Asteroid collision

We are given an array of asteroids of integers representing asteroids in a row.

For each asteroid, the absolute value represents the size, and the sign represents its direction (positive meaning right direction, negative meaning left direction). Each asteroid moves at the same speed.

Find out the state of the asteroids after all collisions. If two asteroids meet, the smaller one will explode. If both are the same size, both will explode. Two asteroids moving in the same direction will never meet.

Examples

// Example 1
const asteroids = [5, 10, -5]
asteroidColitions(asteroids)
// Produces [5, 10]
// Explanation: The 10 and -5 collide resulting in 10. The 5 and 10 never collide.


// Example 2
const asteroids = [8, -8]
asteroidColitions(asteroids)
// Produces []
//Explanation: The 8 and -8 collide exploding each other.


// Example 3
const asteroids = [10, 2, -5]
asteroidColitions(asteroids)
// Produces [10]
// The 2 and -5 collide resulting in -5. The 10 and -5 collide resulting in 10.

Time Format

Create a function called time that takes an integer representing the time value in a human-readable format based on the input value.

The possible units to display the time are as follows:

• s (seconds): 0s, 1s, 2s, ..., 59s
• m (minutes): 1m, 2m, ..., 59m (equivalent to 60 seconds)
• h (hours): 1h, 2h, ..., 23h (equivalent to 60 minutes)
• d (days): 1d, 2d, ..., 6d (equivalent to 24 hours)
• w (weeks): 1w, 2w, ... (equivalent to 7 days)
• y (year) 1y, 2y, ... (equivalent to 365 days)

In case the input is not an exact match for any unit, it should display the largest unit followed by the next unit only if it is consecutive.

Examples:

• time(0) => "0s"
• time(60) => "1m"
• time(3600) => "1h"
• time(3600 * 24) => "1d"
• time(3600 * 24 * 7) => "1w"
• time(3600 * 24 * 365) => "1y"
• time(65) => "1m 5s"
• time(3669) => "1h 1m 9s"
• time(3609) => "1h" (only hours are displayed as there are no minutes)

How to contribute

If you wish to contribute to this project please do the next steps:

1. Create a new issue in Github explaining what is the purpose of your contribution. For example: Adding new exercises, Fixing typos, etc..

2. Create a new branch with the following name convention: {issue_number}-{description} (e.g 123-fix-typo-in-readme)

3. Modify the code and push your branch to GitHub.

4. Create a new Pull Request and assign bcisneros as the Approver and optionally other team members. Select master as the destination branch.

5. The Pull Request will be reviewed and if there are no comments or suggestions the changes will be merged to master

6. You will be added to the Contributors List.