stack.java

<算法导论>第二版大部分算法实现. 1. 各类排序和顺序统计学相关 2. 数据结构 2.1 基本数据结构 2.2 散列表 2.3 二叉查找树 2.4 红黑树 2.5 数据结构

/*
 * Copyright (C) 2000-2007 Wang Pengcheng <[e-mail]>
 * Licensed to the Wang Pengcheng under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The LGPL licenses this file to You under the GNU Lesser General Public
 * Licence, Version 2.0  (the "License"); you may not use this file except in
 * compliance with the License.  You may obtain a copy of the License at
 *
 *     http://www.gnu.org/licenses/lgpl.txt
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
//22 Nov 2007
package cn.edu.whu.iss.algorithm.unit10;

import mypackage.tools.print.*;

public class Stack<T> {
	private Object[] s ;
	private int top;
	
	public Stack(int n){
		s = new Object[n];
		top=0;
	}
	
	public boolean isEmpty(){
		return (top<=0);
	}
	
	public boolean isFull(){
		return (top==s.length);
	}
	
	public  synchronized boolean push(T o) {
		if(isFull()){
			P.rintln("Top flow");
			return false;
		}else{
			s[top] = o;
			top++;
			return true;
		}
	}
	
	public synchronized  T pop() {
		if (!isEmpty()) {
			top--;
			return (T)s[top];
		} else {
			System.err.println("The stack is empty!");
			return null;
		}
	}

	/**
	 * Print every object in the stack [under-stack ...... top-stack]
	 */
	public String toString(){
		if(isEmpty()){
			return "[]";
		}
		String t = "[";
		for(int i=0;i<top-1;i++){
			t+=s[i]+",";
		}
		t+=s[top-1]+"]";
		return t;
	}
	
}