challenge04.md

Challenge #4: 🎄 Decorating the Christmas tree

Level: 🟠 MEDIUM

Instructions

It's time to put up the Christmas tree at home! 🎄 But this year we want it to be special. We're going to create a function that receives the height of the tree (a positive integer between 1 and 100) and a special character to decorate it.

The function should return a string that represents the Christmas tree, constructed as follows:

• The tree is made up of triangles of special characters.
• The spaces on the sides of the tree are represented with underscores _.
• All trees have a trunk of two lines, represented by the # character.
• The tree should always have the same length on each side.
• You must ensure the tree has the correct shape using line breaks \n for each line.

Examples:

const tree = createXmasTree(5, '*')
console.log(tree)
/*
____*____
___***___
__*****__
_*******_
*********
____#____
____#____
*/

const tree2 = createXmasTree(3, '+')
console.log(tree2)
/*
__+__
_+++_
+++++
__#__
__#__
*/

const tree3 = createXmasTree(6, '@')
console.log(tree3)
/*
_____@_____
____@@@____
___@@@@@___
__@@@@@@@__
_@@@@@@@@@_
@@@@@@@@@@@
_____#_____
_____#_____
*/

Solutions

• JavaScript

  function createXmasTree(height, ornament) {
    let xmasTree = ''
    const width = height * 2 -1
    const spaces = '_'.repeat(height - 1)
  
    for (let i = 1; i <= width; i += 2) {
      const _ = '_'.repeat((width - i) / 2)
      xmasTree += `${_}${ornament.repeat(i)}${_}\n`
    }
  
    return `${xmasTree}${spaces}#${spaces}\n${spaces}#${spaces}`
  }

• TypeScript

  function createXmasTree(height: number, ornament: string): string {
    let xmasTree: string = ''
    const spaces: string = '_'.repeat(height - 1)
  
    for (let i = 1; i <= height; i++) {
      const spaces: string = '_'.repeat(height - i)
      const ornaments: string = ornament.repeat(i * 2 - 1)
      xmasTree += `${spaces}${ornaments}${spaces}\n`
    }
  
    xmasTree += `${spaces}#${spaces}\n${spaces}#${spaces}`
  
    return xmasTree
  }

• Python

  def createXmasTree(height, ornament):
    xmas_tree = ""
    trunk_spaces = '_' * height - 1
  
    for i in range(1, height + 1):
      spaces = '_' * height - i
      ornaments = ornament * (i * 2 - 1)
      xmas_tree += spaces + ornaments + spaces + '\n'
    
    xmas_tree += trunk_spaces + '#' + trunk_spaces + '\n'
    xmas_tree += trunk_spaces + '#' + trunk_spaces
  
    return xmas_tree