wordFunnel

// https://www.reddit.com/r/dailyprogrammer/comments/98ufvz/20180820_challenge_366_easy_word_funnel_1/

const fs = require('fs');
const { promisify } = require('util');

const readFilePromise = promisify(fs.readFile);

const makeWordSet = async file => new Set((await promisify(fs.readFile)(file, 'utf8')).split('\n'));

function funnel(word1, word2) {
  for (let i = 0; i < word1.length; i += 1) {
    if (word1.slice(0, i) + word1.slice(i + 1) === word2) {
      return true;
    }
  }
  return false;
}
async function bonus(word) {
  const wordSet = await makeWordSet('enable-word-list.txt');
  const included = new Set();
  for (let i = 0; i < word.length; i += 1) {
    const slice = word.slice(0, i) + word.slice(i + 1);
    if (wordSet.has(slice)) {
      included.add(slice);
    }
  }
  return Array.from(included);
}

async function bonus2() {
  const wordSet = await makeWordSet('enable-word-list.txt');
  const has5 = new Set();
  for (const word of wordSet) {
    const included = new Set();
    for (let i = 0; i < word.length; i += 1) {
      const slice = word.slice(0, i) + word.slice(i + 1);
      if (wordSet.has(slice)) {
        included.add(slice);
      }
    }
    if (included.size === 5) {
      has5.add(word);
    }
  }
  return Array.from(has5);
}

async function start() {
  console.log(funnel('boats', 'boat'));
  console.log(await bonus('boats'));
  const startTime = Date.now();
  const result = await bonus2();
  console.log(result, result.length);
  console.log(`bonus2: ${Date.now() - startTime} ms`);
}

start();