389.find-the-difference.js

/*
 * @lc app=leetcode id=389 lang=javascript
 *
 * [389] Find the Difference
 *
 * https://leetcode.com/problems/find-the-difference/description/
 *
 * algorithms
 * Easy (54.71%)
 * Likes:    762
 * Dislikes: 278
 * Total Accepted:    192.7K
 * Total Submissions: 350.7K
 * Testcase Example:  '"abcd"\n"abcde"'
 *
 *
 * Given two strings s and t which consist of only lowercase letters.
 *
 * String t is generated by random shuffling string s and then add one more
 * letter at a random position.
 *
 * Find the letter that was added in t.
 *
 * Example:
 *
 * Input:
 * s = "abcd"
 * t = "abcde"
 *
 * Output:
 * e
 *
 * Explanation:
 * 'e' is the letter that was added.
 *
 */

// @lc code=start
/**
 * @param {string} s
 * @param {string} t
 * @return {character}
 */
// t is always 1 character longer
/**
 * @param {string} s
 * @param {string} t
 * @return {character}
 */
var findTheDifference = function (s, t) {
  let sum1 = 0;
  for (let i = 0; i < s.length; i++) {
    sum1 += s[i].charCodeAt();
  }

  let sum2 = 0;
  for (let i = 0; i < t.length; i++) {
    sum2 += t[i].charCodeAt();
  }

  return String.fromCharCode(sum2 - sum1);
};
// @lc code=end