Algorithm
LeetCode 75
Reverse Vowels of a String

345. Reverse Vowels of a String

Tags

  • Two Pointers
  • String

Link

https://leetcode.com/problems/reverse-vowels-of-a-string/description/?envType=study-plan-v2&envId=leetcode-75 (opens in a new tab)

Question

Given a string s, reverse only all the vowels in the string and return it.

The vowels are 'a', 'e', 'i', 'o', and 'u', and they can appear in both lower and upper cases, more than once.

Example 1:
Input: s = "IceCreAm"

Output: "AceCreIm"

Explanation:

The vowels in s are ['I', 'e', 'e', 'A']. On reversing the vowels, s becomes "AceCreIm".
Example 2:
Input: s = "leetcode"

Output: "leotcede"
Constraints:
  • 1 <= s.length <= 3 * 105
  • s consist of printable ASCII characters.

Answer

JavaScript

/**
 * @param {string} s
 * @return {string}
 */
var reverseVowels = function (s) {
  const vows = s.match(/[aeiou]/gi);
  return s.replace(/[aeiou]/gi, () => vows.pop());
};
/**
 * @param {string} s
 * @return {string}
 */
var reverseVowels = function (s) {
  var vowels = "aeiouAEIOU";
  s = s.split("");
 
  var i = 0;
  var j = s.length - 1;
 
  while (i < j) {
    if (!vowels.includes(s[i])) {
      i++;
    } else if (!vowels.includes(s[j])) {
      j--;
    } else {
      [s[i], s[j]] = [s[j], s[i]];
      i++;
      j--;
    }
  }
  return s.join("");
};
Product of Array except SelfReverse Words in a String