challenge169

challenge169.js

// /r/dailyprogrammer challenge #169 (http://redd.it/29od55)
// Word list from https://dotnetperls-controls.googlecode.com/files/enable1.txt

var wordlist = require('fs').readFileSync('./dict', 'utf8').split(/\n+/)
                            .filter(function(e) { return e; });
console.log(challenge169(process.argv[2] || 'A oweaib who fprd not zfqzh challenges should mt ewlst to kze', wordlist));

function challenge169(string, wordlist) {
  var shift = function(characters, start, end) {
    for (var n = start, _ret = []; n < end; n++) {
      _ret.push(characters.split('').map(function(e) {
        var row = ['qwertyuiop', 'asdfghjkl', 'zxcvbnm']
          .filter(function(r) { return r.indexOf(e) !== -1; }).pop();
        return row[(((row.indexOf(e) + n) % row.length) + row.length) % row.length];
      }).join(''));
    }
    return _ret;
  };
  return string.replace(/\b[a-zA-Z]+\b/g, function(word) {
    if (wordlist.indexOf(word.toLowerCase()) !== -1) {
      return word;
    }
    return '{' + shift(word.toLowerCase(), -2, 3).filter(function(e) {
      return wordlist.indexOf(e) !== -1;
    }).join(', ') + '}';
  });
}