官方链接
编写一个函数，其作用是将输入的字符串反转过来。输入字符串以字符数组 char[] 的形式给出。
不要给另外的数组分配额外的空间，你必须原地修改输入数组、使用 O(1) 的额外空间解决这一问题。
你可以假设数组中的所有字符都是 ASCII 码表中的可打印字符。
示例 1：
输入：["h","e","l","l","o"]
输出：["o","l","l","e","h"]示例 2：
输入：["H","a","n","n","a","h"]
输出：["h","a","n","n","a","H"]解法一
class Solution {
public void reverseString(char[] s) {
int n = s.length;
for (int i = 0; i < n/2; i++) {
char c = s[i];
s[i] = s[n-i-1];
s[n-i-1] = c;
}
}
}
class Solution {
public void reverseString(char[] s) {
for (int i = 0, j = s.length - 1; i < j; i++, j--) {
char c = s[i];
s[i] = s[j];
s[j] = c;
}
}
}