题解 | #字符逆序#
字符逆序
https://www.nowcoder.com/practice/cc57022cb4194697ac30bcb566aeb47b
import java.util.Scanner; // 注意类名必须为 Main, 不要有任何 package xxx 信息 public class Main { public static String reverseString(String str) { if (str == null || str.isEmpty()) { return str; } char[] charArray = str.toCharArray(); int left = 0; int right = charArray.length - 1; while (left < right) { // 交换字符 char temp = charArray[left]; charArray[left] = charArray[right]; charArray[right] = temp; // 移动左右指针 left++; right--; } return new String(charArray); } public static void main(String[] args) { Scanner in = new Scanner(System.in); // 注意 hasNext 和 hasNextLine 的区别 System.out.println(reverseString(in.nextLine())); } }