valid-word-abbreviation.js

/**
 * Valid Word Abbreviation
 *
 * Given a non-empty string s and an abbreviation abbr,
 * return whether the string matches with the given abbreviation.
 *
 * A string such as "word" contains only the following valid abbreviations:
 *
 * ["word", "1ord", "w1rd", "wo1d", "wor1", "2rd", "w2d", "wo2", "1o1d", "1or1", "w1r1", "1o2", "2r1", "3d", "w3", "4"]
 * Notice that only the above abbreviations are valid abbreviations of the string "word".
 * Any other string is not a valid abbreviation of "word".
 *
 * Note:
 * Assume s contains only lowercase letters and abbr contains only lowercase letters and digits.
 *
 * Example 1:
 * Given s = "internationalization", abbr = "i12iz4n":
 *
 * Return true.
 * Example 2:
 * Given s = "apple", abbr = "a2e":
 *
 * Return false.
 */

/**
 * @param {string} word
 * @param {string} abbr
 * @return {boolean}
 */
const validWordAbbreviation = (word, abbr) => {
  const m = word.length;
  const n = abbr.length;

  let i = 0;
  let j = 0;

  while (i < m && j < n) {
    if (abbr[j] >= '1' && abbr[j] <= '9') {
      let count = 0;
      while (abbr[j] >= '0' && abbr[j] <= '9') {
        count = count * 10 + (abbr[j] - '0');
        j++;
      }
      i += count;
    } else if (word[i] === abbr[j]) {
      i++;
      j++;
    } else {
      return false;
    }
  }

  return i === m && j === n;
};

export { validWordAbbreviation };