队列：队列其实就是我们生活中的排队现象，先进入的先出，后进入的后出，代码实现如下：

public class Queue {

private int front;//队头一端，只允许删除

private int rear;//队尾一端，只允许插入操作

private int max_size =16;

private Object[] data;

public Queue() {

this(10);

}

public Queue(int size){

if(size<0){

throw new IllegalArgumentException("队列初始化失败，原因是："+size);

}

this.max_size = size;

front = rear = 0;

data = new Object[max_size];

}

//判断是否为空

public boolean isEmpty(){

return rear==front?true:false;

}

//入队

public boolean add(E e){

if(rear==max_size){

throw new RuntimeException("队列满了");

}else{

data[rear++] = e;

return true;

}

}

//返回队首元素,不删除元素

public E peek(){

if(isEmpty()){

return null;

}

return (E) data[front];

}

//出队

public E poll(){

if(isEmpty()){

throw new RuntimeException("队列为空");

}

else{

E e = (E) data[front];

data[front++] = null;

return e;

}

}

//长度

public int length(){

return rear-front;

}

}

public class Queue {

private Object[] data; //存储数据

private int head; //头

private int tail; //尾

public Queue(){

data = new Object[100];//为了说明原理随意指定

head =1;

tail =1;

}

public void put(T t){

data[tail] =t;

tail++;

}

public T get(){

T t =(T) data[head];

head ++;

return t;

}

}

栈：

package test;

public class stack {

private int maxSize;// 栈的大小

private int top;

private char[] arr;

public stack(int size) {

maxSize = size;

top = -1;

arr = new char[maxSize];

}

public void push(char value) { // 压入数据

arr[++top] = value;

}

public char pop() { // 弹出数据

return arr[top--];

}

public char peek() { // 访问栈顶元素

return arr[top];

}

public boolean isFull() { // 栈是否满了

return maxSize - 1 == top;

}

public boolean isEmpty() { // 栈是否为空

return top == -1;

}

}