Reverse Vowels of a String

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”.

代碼：

//遍歷字符串，temp數組順序存儲元音字母；
//再遍歷字符串，碰到元音字母從temp數組最後元素往前替換

char* reverseVowels(char* s) {
    if(strlen(s) <= 1)  return s;
    char *head = s;
    char *temp = (char *)malloc(strlen(s) * sizeof(char));
    int i = 0;
    char str[11] = "aAeEiIoOuU";

    while(*s != '\0')
    {
     //strchr() 在一個字符串中查找另一個字符串第一次出現的位置，找到返回這個字符指針，找不到返回NULL；
        if(NULL != strchr(str, *s)) 
            temp[i++] = *s;
        s++;
    }
    s = head;

    while(*s != '\0')
    {
         if(NULL != strchr(str, *s))
             *s = temp[--i];
         printf("%d\n", i);
        s++;
    }
    return head;
}