字符串逆序输出使用堆栈，将一个由命令行输入的字符串逆序输出。

System.out.println("Input the String:");
Scanner in = new Scanner(System.in);
String str = in.nextLine();
Stack<Character> stack = new Stack<Character>();
for (int i =0; i < str.length(); i++)
stack.push(str.charAt(i));

while (!stack.empty())
System.out.print(stack.pop());