345. 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".
Note:
The vowels does not include the letter "y".
Solution 1:
class Solution {
public String reverseVowels(String s) {
if (s == null || s.length() == 0)
return s;
String vowels = "aeiouAEIOU";
char[] ch = s.toCharArray();
int start = 0;
int end = s.length() - 1;
while (start < end) {
while (start < end && !vowels.contains(ch[start]+"")) { //这里必须要加start < end，否则在交换之后又会换回来，这里只能是<，不能=，否则后面ch[start]会有越界异常
start++;
}
while (start < end && !vowels.contains(ch[end]+"")) {//这里必须要加start < end
end--;
}
char temp = ch[start];
ch[start] = ch[end];
ch[end] = temp;
start++;
end--;
}
return new String(ch);
}
}
