917. 仅仅反转字母

https://leetcode-cn.com/problems/reverse-only-letters/

执行用时：0 ms, 在所有 Java 提交中击败了100.00% 的用户
内存消耗：39.4 MB, 在所有 Java 提交中击败了12.78% 的用户
通过测试用例：115 / 115

class Solution {
    public String reverseOnlyLetters(String s) {
        int left = 0, right = s.length() -1;
        char[] str = s.toCharArray();
        while (left < right) {
            char leftCh = s.charAt(left);
            char rightCh = s.charAt(right);
            if (Character.isLetter(leftCh) && Character.isLetter(rightCh)) {
                char temp = str[left];
                str[left] = str[right];
                str[right] = temp;
                left++;
                right--;
            }
            if (!Character.isLetter(leftCh)) {
                left++;
            }
            if (!Character.isLetter(rightCh)) {
                right--;
            }
        }
        return new String(str);
    }
}