Java实现栈-顺序栈&链式栈

Java实现顺序栈

package sequence;

//java实现顺序栈
public class SeqStack<T> {

	private int top = 0;
	private int capacity;
	private T[] elementData;
	private static final int DEAFAULT_CAPACITY = 4;
	
	public SeqStack(){
		capacity = DEAFAULT_CAPACITY;
		elementData = (T[])(new Object[capacity]);
	}

	public SeqStack(int capacity){
		this.capacity = capacity;
		elementData = (T[])new Object[capacity];
	}
	public SeqStack(T element){
		this();
		elementData[0] = element;
		top++;
	}
	public SeqStack(T element,int capacity){
		this.capacity = capacity;
		elementData = (T[]) new Object[capacity];
		elementData[0] = element;
		top++;
	}
	
	public boolean isEmpty(){
		return top == 0;
	}
	public boolean isFull(){
		return top == capacity;
	}
	
	public boolean push(T element){
		if(isFull()){
			return false;
		}
		elementData[top++] = element;
		return true;
		
	}
	
	public T pop(){
		if(isEmpty()){
			throw new IndexOutOfBoundsException("栈为空");
		}
		return elementData[--top];
		
	}
	
	public T peek(){
		if(isEmpty()){
			throw new IndexOutOfBoundsException("栈为空");
		}
		return elementData[top - 1];
	}
	
	public void traverse(){
		for(int i=0;i<top;i++){
			System.out.println(elementData[i]);
		}
	}
	
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		SeqStack<String> ss = new SeqStack<>("aaa",3);
		ss.push("bbb");
		ss.push("ccc");
		ss.traverse();
		System.out.println("=======");
		ss.push("ddd");
		ss.traverse();
		
	}

}

Java实现链式栈

 

package link;

public class LinkStack<T> {

	class Node{
		private T data;
		private Node next;
		
		public Node(){}
		public Node(T data,Node next){
			this.data = data;
			this.next = next;
		}
		
	}
	
	private Node top;	//栈顶元素
	private int size;
	
	public LinkStack(){
		top = null;
	}
	public LinkStack(T element){
		top = new Node(element,null);
		size++;
	}
	
	public int getSize(){
		return size;
	}
	public void push(T element){
		top = new Node(element,top);
//		top = node;
		size++;
	}
	public T pop(){
		Node old = top;
		top = top.next;
		old.next = null;
		size--;
		return old.data;
	}
	public T peek(){
		return top.data;
	}
	public boolean isEmpty(){
		return size == 0;
	}
	public void clear(){
		top = null;
		size = 0;
	}
	public void traverse(){
		for(Node current = top;current != null;current = current.next){
			System.out.println(current.data);
		}
	}
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		LinkStack<String> ls = new LinkStack<>();
		ls.push("aaa");
		ls.push("bbb");
		ls.traverse();
		System.out.println("====");
//		System.out.println(ls.peek());
		ls.pop();
		ls.push("ccc");
		ls.traverse();
	}

}

栈应用实例

进制转换

package sequence;

import java.util.Scanner;

public class Convert {
	//将一个数转化为16进制
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		//转化为十六进制因为栈中存放的是小于16的余数，这里要定义数组使余数与下标对应
		char num[] = {'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};
		SeqStack<Integer> sq = new SeqStack<>(10);
		
		System.out.println("请输入要转化的十进制数");
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int result = 0;
		while(n != 0){
			result = n%16;
			sq.push(result); 
			n = n / 16;
		}
		
		while(!sq.isEmpty()){
			int number = sq.pop();
			System.out.print(num[number]);
		}
		System.out.println();
		
	}

}

括号匹配

package sequence;

public class Match {

	
	
	public static void main(String[] args) {
		String str = "[({})]";
		SeqStack<Character> test = new SeqStack<>(20);
		int flag = 0;
		for(int i=0;i<str.length();i++){
			char ch = str.charAt(i);
			switch(ch){
				case '(':
					test.push(ch);
					break;
				case '[':
					test.push(ch);
					break;
				case '{':
					test.push(ch);
					break;
				case ')':
					if(test.isEmpty()){
						flag = 1;
					}else{
						if(test.pop() == '('){
						}else{
							flag = 1;
						}
					}
					
					break;
				case ']':
					if(test.isEmpty()){
						flag = 1;
					}else{
						if(test.pop() == '['){
						}else{
							flag = 1;
						}
					}
					break;
				case '}':
					if(test.isEmpty()){
						flag = 1;
					}else{
						if(test.pop() == '{'){
						}else{
							flag = 1;
						}
					}
					break;
			}
		}
		if(test.isEmpty() && flag == 0){
			System.out.println("字符串匹配正确");
		}else{
			System.out.println("匹配错误");
		}
	}

}