288__medium__unique-word-abbreviation.js

/**
 * @param
 * @return
 */

/**
 *
 * O(n) time preprocess
 * O(n) space for map
 * O(1) for isUnique() call
 *
 * 45m
 */

/*
    =================== solution 1 (115ms) ===================
*/
/**
 * @param {string[]} NOTE: dictionary is unique here!!!
 */
var ValidWordAbbr = function(dictionary) {
  this.map = new Map();
  for (let i = 0; i < dictionary.length; i++) {
    let w = dictionary[i];
    if (w.length < 3) this.map.set(w, [w]);
    else {
      let key = this.toAbbr(w);
      let group = this.map.get(key) || [];
      group.push(w);
      this.map.set(key, group);
    }
  }
};

/**
 * @param {string} word
 * @return {boolean}
 */
ValidWordAbbr.prototype.isUnique = function(word) {
  let len = word.length;
  if (len < 3) return true;
  let key = this.toAbbr(word);
  if (this.map.has(key)) {
    let group = this.map.get(key);
    if (group.length === 1) return group[0] === word;
    return false;
  }
  return true;
};

ValidWordAbbr.prototype.toAbbr = word => {
  let len = word.length;
  if (len < 3) return word;
  return word[0] + (len - 2) + word[len - 1];
};
/**
 * Your ValidWordAbbr object will be instantiated and called as such:
 * var obj = Object.create(ValidWordAbbr).createNew(dictionary)
 * var param_1 = obj.isUnique(word)
 */

/*
    =================== solution 2 (96ms) ===================
*/
/**
 * @param {string[]} dictionary is unique
 */
var ValidWordAbbr = function(dictionary) {
  this.map = new Map();
  for (let i = 0; i < dictionary.length; i++) {
    let w = dictionary[i];
    if (w.length < 3) this.map.set(w, true);
    else {
      let key = this.toAbbr(w);
      let val = this.map.has(key) ? false : w;
      this.map.set(key, val);
    }
  }
};

/**
 * @param {string} word
 * @return {boolean}
 */
ValidWordAbbr.prototype.isUnique = function(word) {
  let len = word.length;
  if (len < 3) return true;

  let key = this.toAbbr(word);
  if (this.map.has(key)) {
    let val = this.map.get(key);
    if (val === false) return false;
    return word === val;
  }
  return true;
};

ValidWordAbbr.prototype.toAbbr = word => {
  let len = word.length;
  if (len < 3) return word;
  return word[0] + (len - 2) + word[len - 1];
};

/**
 * Your ValidWordAbbr object will be instantiated and called as such:
 * var obj = Object.create(ValidWordAbbr).createNew(dictionary)
 * var param_1 = obj.isUnique(word)
 */