AI solution for JavaScript Coding Question on BFE.dev
165. remove characters

One possible solution in JavaScript is:

function removeChars(str) {
  let result = '';
  for (let i = 0; i < str.length;) {
    if (str[i] === 'a') {
      if (str[i + 1] === 'c') {
        i += 2; // skip 'ac'
      } else {
        result += 'a'; // keep 'a'
        i++;
      }
    } else if (str[i] === 'b') {
      i++; // skip 'b'
    } else {
      result += str[i]; // keep 'c'
      i++;
    }
  }
  return result;
}

The function uses a loop to iterate through the characters of the input string, and checks each character to see if it should be removed or kept. If the character is an a, it checks the next character to see if it's a c, in which case both characters are skipped. Otherwise, the a is kept. If the character is a b, it is simply skipped. And if the character is a c, it is kept.

The time complexity of the function is O(n), where n is the length of the input string, because it needs to iterate through all the characters of the string once. The space complexity of the function is O(n) as well, because it creates a result string that can be as long as the input string.