Stack的简单应用

栈（Stack）的简单应用：

构建Stack，接口方法有push(), pop(), peek(), isEmpty()等，使用LinkedList来创建Stack，如下：

class Stack<T> {private LinkedList<T> list = new LinkedList<T>();public void push(T elem) {list.addFirst(elem);}public T pop() {return list.removeFirst();}public T peek() {return list.getFirst();}public boolean isEmpty() {return list.isEmpty();}public String toString() {return list.toString();}}

以字符串简单测试下：

public class stackTest {static public void main(String[] args) {boolean bPushElem = false;Stack<String> stack1 = new Stack<String>();String originStr = "+U+n+c---+e+r+t---+a-+i-+n+t+y---+~-+r+u--+l+e+s";System.out.println(originStr);for (String s: originStr.split("")) {if (s.equals("+")) {bPushElem = true;continue;} else if(s.equals("-")) {stack1.pop();System.out.println(stack1);} else if (s.equals(" ")) {continue;} else {if (bPushElem) {stack1.push(s);System.out.println(stack1);}bPushElem = false;}}System.out.println(stack1);}}