LeetCode 344 Reverse String

題意

翻轉字符串。

解法

兩個指針，分別在首和尾，都向中間走，直到首超過尾。

class Solution {
    public String reverseString(String s) {
        char[] chars = s.toCharArray();
        for (int i = 0, j = chars.length - 1; i < j; i++, j--) {
            char temp = chars[i];
            chars[i] = chars[j];
            chars[j] = temp;
        }
        return new String(chars);
    }
}

Runtime: 2 ms, faster than 79.62% of Java online submissions for Reverse String.