algorithms.html

<!DOCTYPE html>
<html>
<body>

<script>

function reverseString(s) {
  return s.split("").reverse().map(c => {
    if (c === '(') {
      return ')';
    } else if (c === ')') {
      return '(';
    }
    return c;
  }).join("");
}

function readAndReverseInsideParens(s, cursor) {
  var accum = "";
  
  while (cursor<s.length) {
    var c = s[cursor];

    // shift cursor right 
    cursor = cursor + 1; 

    // if the opening parens, call the recursive function
    if (c == "(") {
      var subStr;
      [subStr, cursor] = readAndReverseInsideParens(s, cursor);
      accum = accum + '(' + reverseString(subStr) + ')'; 
    } else if (c==")") {
      break;
    } else {
      accum = accum + c;
    }
  }
  return [accum, cursor]; 
}

function reverseInParens(text){
  var [reversed, cursor] = readAndReverseInsideParens(text, 0);
  return reversed;
}

console.log(reverseInParens("h(el)lo"), "h(le)lo");
console.log(reverseInParens("a ((d e) c b)"), "a (b c (d e))");
console.log(reverseInParens("one (two (three) four)"), "one (ruof (three) owt)");
console.log(reverseInParens("one (ruof ((rht)ee) owt)"), "one (two ((thr)ee) four)");

</script>

</body>
</html>