題目

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

Example 1:
Given s = "hello", return "holle".

Example 2:
Given s = "leetcode", return "leotcede".

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

解題思路

1. 從兩端遍歷字符串，分別找到一個元音字母s[i], s[j]，i < j, 然后交換兩個字符；
2. i, j = i+1, j-1 ；繼續執行同樣的操作，直至遍歷完字符串

代碼

func isVowels(r rune) bool {
    if r == rune('a') || r == rune('e') || r == rune('i') || r == rune('o') || r == rune('u') || r == rune('A') || r == rune('E') || r == rune('I') || r == rune('O') || r == rune('U'){
        return true
    }
    return false
}

func reverseVowels(s string) string {
    len1 := len(s)
    runeS := []rune(s)
    for i, j := 0, len1-1; i < j; i, j = i+1, j-1{
        for ;!isVowels(runeS[i]) && i < len1-1; i++ {}
        fmt.Printf("i:%+v\n", i)
        for ;!isVowels(runeS[j]) && j > 0; j-- {}

        if i < j {
            runeS[i], runeS[j] = runeS[j], runeS[i]
        }
    }

    ret := string(runeS)

    fmt.Printf("ret:%+v\n", ret)
    return ret
}