345. Reverse Vowels of a String

Description of Problem

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 = "hello"
Output: "holle"

Example 2:

Input: s = "leetcode"
Output: "leotcede"

Constraints:

• 1 <= s.length <= 3 * 10^5
• s consist of printable ASCII characters.

Solution

Code (Rust)

impl Solution {
    pub fn reverse_vowels(s: String) -> String {
        let mut s = s;    
            let mut bytes = unsafe { s.as_bytes_mut() };
            let (mut i, mut j) = (0, bytes.len() - 1);

            while (i < j){
                match (bytes[i], bytes[j]) {
                    (65|69|73|79|85|97|101|105|111|117, 65|69|73|79|85|97|101|105|111|117) => {
                        let temp = bytes[i];
                        bytes[i] = bytes[j];
                        bytes[j] = temp;
                        i+=1; j-=1;
                        
                    },
                    (65|69|73|79|85|97|101|105|111|117, _) => {
                        j-=1;
                    },
                    (_, 65|69|73|79|85|97|101|105|111|117) => {
                        i+=1;
                    },
                    (_,_) => { i+=1; j-=1; }
                }
            }

        return s;
    }
}

Complexity

• n is length of string

Time Complexity

• \(T(n)=O(n)\)

Auxiliary Space

• \(S(n)=O(1)\)