简单链表操作-java实现

节点结构链表队列

class Node{
	int val;
	Node next;
	
	public int getVal() {
		return val;
	}
	public void setVal(int val) {
		this.val = val;
	}
	public Node getNext() {
		return next;
	}
	public void setNext(Node next) {
		this.next = next;
	}
	public Node(int val) {
		this.val = val;
	}
	public Node() {}
}

public class linkUtil {
	private Node data = null;
	private int size = 0;
	
	public void add(int val) {
		Node node = new Node(val);
		
		if( data == null ) {
			data = node;
			size++;
			return;
		}
		Node front = data;
		
		while(front.next != null) {
			front = front.next;
		}
		front.next = node;
		size++;
	}
	
	public void delete(int index) {
		if(index >= size) {
			throw new RuntimeException("超出长度");
		}
		if(size <= 1) {
			data = null;
			size = 0;
			return;
		}
		
		Node pre = new Node();
		pre.next = data;
		Node now = data;
		
		Node head = pre;
		int i = 0;
		while(now != null) {
			if(i == index) {
				pre.next = now.next;
				break;
			}
			pre = now;
			now = now.next;
			i++;
		}
		
		data = head.next;
	}
	
	
	public int get(int index) {
		if(index >= size) {
			throw new RuntimeException("超出长度");
		}
		
		Node front = data;
		int i = 0;
		while(front != null) {
			if(i == index) {
				return front.val;
			}
			front = front.next;
			i++;
		}
		throw new RuntimeException("异常");
		
	}
	
	public Node getlink() {
		return data;
	}
	
	public int size() {
		return size;
	}
}

public class QueueUtil {
	private Node data;
	private int size = 0;
	
	private Node head;
	private Node front;
	
	public void push(int val) {
		Node node = new Node(val);
		
		if( data == null ) {
			data = node;
			size++;
			head=data;
			front = data;
			return;
		}
		
		front.next = node;
		front = node;
		size++;
	}
	
	
	public Integer pop() {
		if(head == null) {
			return null;
		}
		int val = head.val;
		head = head.next;
		size--;
		return val;
	}
	
	public int size() {
		return size;
	}
	
}