challenge16.md

Challenge #16: ❄️ Cleaning the snow path

Level: 🟢 EASY

Instructions

The elves are working hard to clear paths filled with magical snow ❄️. This snow has a special property: if two identical and adjacent snow piles are found, they disappear automatically.

Your task is to write a function to help the elves simulate this process. The path is represented by a string and each snow pile by a character.

You need to remove all adjacent snow piles that are the same until no more moves are possible.

The result should be the final path after removing all duplicate piles:

Examples:

removeSnow('zxxzoz') // -> "oz"
// 1. Remove "xx", resulting in "zzoz"
// 2. Remove "zz", resulting in "oz"

removeSnow('abcdd') // -> "abc"
// 1. Remove "dd", resulting in "abc"

removeSnow('zzz') // -> "z"
// 1. Remove "zz", resulting in "z"

removeSnow('a') // -> "a"
// No duplicate piles

Solutions

• JavaScript

  /**
  * @param {string} s
  * @returns {string}
  */
  function removeSnow(s) {
    return [...s].reduce((r, c) => [r + c, r.slice(0, -1)][+r.endsWith(c)], '')
  }

• TypeScript

  /**
   * @param {string} s
  * @returns {string}
  */
  function removeSnow(s: string): string {
    let clean = ''
    for (const c of s)
      clean = [clean + c, clean.slice(0, -1)][+clean.endsWith(c)]
    return clean;
  }

• Python

  def remove_snow(s):
    clean = ''
    for c in s:
      clean = [clean + c, clean[:-1]][int(clean.endswith(c))]
    return clean