freeCodeCamp/curriculum/challenges/english/08-coding-interview-prep/rosetta-code/abc-problem.english.md

title, id, challengeType

title	id	challengeType
ABC Problem	594810f028c0303b75339acc	5

Description

You are given a collection of ABC blocks (e.g., childhood alphabet blocks). There are 20 blocks with two letters on each block. A complete alphabet is guaranteed amongst all sides of the blocks. The sample collection of blocks:

(B O)

(X K)

(D Q)

(C P)

(N A)

(G T)

(R E)

(T G)

(Q D)

(F S)

(J W)

(H U)

(V I)

(A N)

(O B)

(E R)

(F S)

(L Y)

(P C)

(Z M)

Some rules to keep in mind:

Once a letter on a block is used, that block cannot be used again. The function should be case-insensitive.

Implement a function that takes a string (word) and determines whether the word can be spelled with the given collection of blocks.

Instructions

Tests

tests:
  - text: <code>canMakeWord</code> is a function.
    testString: assert(typeof canMakeWord === 'function', '<code>canMakeWord</code> is a function.');
  - text: <code>canMakeWord</code> should return a boolean.
    testString: assert(typeof canMakeWord('hi') === 'boolean', '<code>canMakeWord</code> should return a boolean.');
  - text: <code>canMakeWord("bark")</code> should return true.
    testString: assert(canMakeWord(words[0]), '<code>canMakeWord("bark")</code> should return true.');
  - text: <code>canMakeWord("BooK")</code> should return false.
    testString: assert(!canMakeWord(words[1]), '<code>canMakeWord("BooK")</code> should return false.');
  - text: <code>canMakeWord("TReAT")</code> should return true.
    testString: assert(canMakeWord(words[2]), '<code>canMakeWord("TReAT")</code> should return true.');
  - text: <code>canMakeWord("COMMON")</code> should return false.
    testString: assert(!canMakeWord(words[3]), '<code>canMakeWord("COMMON")</code> should return false.');
  - text: <code>canMakeWord("squAD")</code> should return true.
    testString: assert(canMakeWord(words[4]), '<code>canMakeWord("squAD")</code> should return true.');
  - text: <code>canMakeWord("conFUSE")</code> should return true.
    testString: assert(canMakeWord(words[5]), '<code>canMakeWord("conFUSE")</code> should return true.');

Challenge Seed

function canMakeWord (word) {
  // Good luck!
}

After Test

const words = ['bark', 'BooK', 'TReAT', 'COMMON', 'squAD', 'conFUSE'];

Solution

function canMakeWord (word) {
  const characters = 'BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM';
  const blocks = characters.split(' ').map(pair => pair.split(''));

  const letters = [...word.toUpperCase()];
  let length = letters.length;
  const copy = new Set(blocks);

  letters.forEach(letter => {
    for (let block of copy) {
      const index = block.indexOf(letter);

      if (index !== -1) {
        length--;
        copy.delete(block);
        break;
      }
    }
  });
  return !length;
}