import java.util.*; //将字符串转成charArray,然后使用交换法来完成反转 public class Main{ public static void main(String[] args){ Scanner scanner = new Scanner(System.in); String str = scanner.nextLine(); char[] charArray = str.toCharArray(); int i = 0; int j = charArray.length-1; char temp; while(i < j){ temp = charArray[i]; charArray[i] =charArray[j]; charArray[j] = temp; i++; j--; } System.out.println(new String(charArray)); } }