Interview

Question 1.js

/*
 * Implement function verify(text) which verifies whether parentheses within text are
 * correctly nested. You need to consider three kinds: (), [], <> and only these kinds.
 */
function verify(string) {
  string = string.replace(/[^\(\)\[\]\{\}\<\>]/g, '');
  let previousString = '';

  while (string.length !== previousString.length) {
    previousString = string;
    string = string.replace(/\(\)|\[\]|\{\}|\<\>/g, '');
  }

  return !string.length;
}

console.log(verify('---(++++)----'));
console.log(verify(''));
console.log(verify('before ( middle [] ) after '));
console.log(verify(') ('));
console.log(verify('<(   > )'));
console.log(verify('(  [  <>  ()   ]  <>   )'));
console.log(verify('   (      [)'));

Question 2.js

/*
 * Simplify the implementation below as much as you can. Even better
 * if you can also improve performance as part of the simplification!
 * FYI: This code is over 35 lines and over 300 tokens, but it can
 * be written in 5 lines and in less than 60 tokens.
 */
function func(s, a, b) {
  var match_empty = /^$/;

  if (s.match(match_empty)) {
    return -1;
  } else {
    var i = s.length - 1;

    var aIndex = -1;

    var bIndex = -1;

    while (aIndex == -1 && bIndex == -1 && i >= 0) {
      if (s.substring(i, i + 1) == a) aIndex = i;

      if (s.substring(i, i + 1) == b) bIndex = i;

      i--;
    }

    if (aIndex != -1) {
      if (bIndex == -1) return aIndex;
      else return Math.max(aIndex, bIndex);
    } else {
      if (bIndex != -1) return bIndex;
      else return -1;
    }
  }
}
console.log(func('abcdefgh', 'a', 'c'));  



function newFunc(s, a, b) {
  return (s.length)
    ? Math.max(s.lastIndexOf(a), s.lastIndexOf(b))
    : -1;
};
console.log(newFunc('abcdefgh', 'a', 'c'));