数据结构学习之栈的Java实现

介绍

顺序栈

package Stack;

/**
* Created by xiaojian on 2017/7/20.
* 顺序栈 入栈 出栈 判空 返回栈顶元素
*/
public class SequenceStack {
private Object[] data = new Object[5];
//    栈顶
private int top=0;
//    元素个数
private int size=0;

//    入栈
public void push(Object o){
if(isFull()){
increStack();
}
data[top++] = o;
size++;
}
//    出栈
public Object pop(){
if(isEmpty()){
throw new RuntimeException("栈空");
}
Object o = data[top-1];
data[--top] = null;
size--;
return  o;
}
//    返回栈顶元素
public Object getTop(){
if(!isEmpty()){
return data[top-1];
}
return null;
}
//    扩容
public void increStack(){
Object[] newData = new Object[data.length * 2];
System.arraycopy(data,0,newData,0,data.length);
data = newData;
}
//    遍历
public void display(){
while(!isEmpty()){
System.out.println(pop());
}
}
//    判空
public boolean isEmpty(){
return size == 0;
}
//    栈满
public boolean isFull(){
return size == data.length;
}

}

链栈

package Stack;

/**
* Created by xiaojian on 2017/7/21.
* 结点类
*/
public class Node {
private Object data;
private Node next;

public Object getData() {
return data;
}

public void setData(Object data) {
this.data = data;
}

public Node getNext() {
return next;
}

public void setNext(Node next) {
this.next = next;
}
}

package Stack;

/**
* Created by xiaojian on 2017/7/20.
* 链栈
*/
public class LinkQueue {
private Node top = null;
private int size =0;

//    进栈
public void push(Object o){
Node node = new Node();
node.setData(o);
if(top==null){
top = node;
}else{
node.setNext(top);
top= node;
}
size++;
}
//    出栈
public Object pop( ){
if(isEmpty()){
throw new RuntimeException("栈空");
}else {
Node node = top;
top = top.getNext();
node.setNext(null);
size -- ;
return node.getData();
}
}
//返回栈顶元素
public Object getTop(){
if(isEmpty()){
throw new RuntimeException("栈空");
}
return top.getData();
}
//  遍历
public void display(){
while(top!=null){
System.out.println(pop());
}
}
public boolean isEmpty(){
return size == 0;
}

}