[Swift]LeetCode345. 反转字符串中的元音字母 | Reverse Vowels of a String

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Write a function that takes a string as input and reverse only the vowels of a string.

Example 1:

Input: "hello"
Output: "holle"

Example 2:

Input: "leetcode"
Output: "leotcede"

Note:
The vowels does not include the letter "y".

---

编写一个函数，以字符串作为输入，反转该字符串中的元音字母。

示例 1:

输入: "hello"
输出: "holle"

示例 2:

输入: "leetcode"
输出: "leotcede"

说明:
元音字母不包含字母"y"。

---

84ms

class Solution {
    func reverseVowels(_ s: String) -> String {
        var a = Array(s)
        var i = 0
        var j = a.count - 1
        
        while i < j {
            if !isVowel(a[i]) {
                i += 1
            } else if !isVowel(a[j]) {
                j -= 1
            } else {
                (a[i], a[j]) = (a[j], a[i])
                i += 1
                j -= 1
            }
        }
        
        return String(a)
    }
    
    func isVowel(_ c: Character) -> Bool {
        switch c {
        case "a","e","i","o","u","A","E","I","O","U":
            return true
        default:
            return false
        }
    }
}

---

120ms

class Solution {
    let vowels: Set<Character> = ["a", "e", "i", "o", "u", "A", "E", "I", "O", "U"]
    func reverseVowels(_ s: String) -> String {
        if s.count < 2 { return s }
        var chars = Array(s)
        var start = 0
        var end = chars.count - 1
        while start < end {
            while start < end && !vowels.contains(chars[start]) {
                start += 1
            }
            
            while end > start && !vowels.contains(chars[end]) {
                end -= 1
            }
            if start != end {
                chars.swapAt(start, end)
                start += 1
                end -= 1
            }
        }
        return String(chars)
    }
}

---

144ms

class Solution {
    func reverseVowels(_ s: String) -> String {
        let set: Set<Character> = [Character("a"), Character("e"), Character("i"), Character("o"), Character("u"),Character("A"), Character("E"), Character("I"), Character("O"), Character("U")]
        var chars = Array(s)
        var left = 0
        var right = s.count - 1
        while left < right {
            if set.contains(chars[left]) && set.contains(chars[right]) {
                chars.swapAt(left, right)
                left += 1
                right -= 1
            } else if set.contains(chars[left]) {
                right -= 1
            } else {
                left += 1
            }
        }

        return String(chars)
    }
}

---

152ms

class Solution {
    func reverseVowels(_ s: String) -> String {
        if s.count == 0 {
           return ""
        }
        
        var chas = s.cString(using:.ascii)!
        
        var left = 0
        var right = s.count - 1
        
        var loop = true
        
        while loop {
            if left > right {
                loop = false
                break
            } 
            
            let leftChar = chas[left]
            
            if !checkIsYuanChar(leftChar) {
                left = left + 1
                continue
            }
            
            let rightChar = chas[right] 
            
            if !checkIsYuanChar(rightChar) {
                right = right - 1
                continue
            }
            
            chas[left] = rightChar
            chas[right] = leftChar
            
            left = left + 1
            right = right - 1
        }
        
        var newStr = String.init(cString:chas)
        
        return newStr
    }
    

    
    func checkIsYuanChar(_ c: CChar) -> Bool {
        if c == 65 || c == 97 {
            return true
        }
        if c == 69 || c == 101 {
            return true
        }
        if c == 73 || c == 105 {
            return true
        }
        if c == 79 || c == 111 {
            return true
        }
        if c == 85 || c == 117 {
            return true
        }
        
        return false
    
    }
}

---

192ms

class Solution {
    func reverseVowels(_ s: String) -> String {
        // a e i o u
        let set: Set<Character> = ["a", "e", "i", "o", "u", "A", "E", "I", "O", "U"]
        var indexArray = [Int]()
        var valueArray = [Character]()
        var array = [Character](s)
        for (index, c) in array.enumerated() {
            if set.contains(c) {
                indexArray.append(index)
                valueArray.append(c)
            }
        }
        let reversed = Array(valueArray.reversed())
        for i in 0 ..< indexArray.count {
            array[indexArray[i]] = reversed[i]
        }
        return String(array)
    }
}

---

260ms

class Solution {
    func reverseVowels(_ s: String) -> String {
        let yuanyin:[Character] = ["a", "e", "i", "o", "u", "A", "E", "I", "O", "U"]
        
        var arr = Array(s)
        
        var left = 0
        var right = s.count - 1
        while left < right {
            
            while !yuanyin.contains(arr[left]) && left < right {
                left += 1
            }
            while !yuanyin.contains(arr[right]) && left < right {
                right -= 1
            }
            
            (arr[left], arr[right]) = (arr[right], arr[left])
            left += 1
            right -= 1
        }
        
        return String(arr)
    }
}

---

428ms

class Solution {
    func reverseVowels(_ s: String) -> String {
        var sArr = Array(s)
        var vowels = [Character]()
        let v = "aeiouAEIOU"
        
        for c in sArr where v.contains(c) {
            vowels.append(c)
        }
        
        for i in 0..<sArr.count  {
            let c = sArr[i]
            if v.contains(c) {
                sArr[i] = vowels.removeLast()
            }
        }
        
        return String(sArr)
    }
}