Java实现单链表

首先定义一个节点类，有两个成员变量：val和next，以及一个构造函数：

/*
 * 单链表非数组实现
 */
public class ListNode {
	ListNode next;
	int val;
	ListNode(int val){
		this.val = val;
		this.next = null;
	}
}

单链表最常用的两个方法就是插入和删除：

public static void main(String[] args) {
		SingleLinkedList LinkedList = new SingleLinkedList();
		ListNode head = new ListNode(0);
		LinkedList.insert(head,1,0);
		LinkedList.insert(head,2,0);
		LinkedList.insert(head,3,0);
		LinkedList.insert(head,4,0);
		LinkedList.insert(head,2,1);
		LinkedList.insert(head,2,2);
		ListNode p = head;
		while(p != null){
			System.out.print(p.val+" ");
			p = p.next;
		}
		System.out.println();
		LinkedList.delete(head,8);
		while(head != null){
			System.out.print(head.val+" ");
			head = head.next;
		}
		
	}
	
	//在第i个元素后插入节点
	public void insert(ListNode head,int i,int val){
		ListNode tail = head;
		int j = 0;
		while(tail != null){
			j++;
			if(i == j){
				ListNode node = new ListNode(val);
				ListNode tailnext = tail.next;//第i个元素后一个节点
				tail.next = node;//插入新的节点
				node.next = tailnext;
				break;
			}
			tail = tail.next;
		}
		if(i>j){  
            System.out.println("超过表长");  
        }
	}
	
	//删除第i个元素
	public void delete(ListNode head,int i){
		ListNode tail = head;
		int j = 0;
		while(tail != null){
			j++;		
			if(j == i-1){
				if(tail.next != null){
					tail.next = tail.next.next;	//删除第i个元素
				}else{//如果超过表长
					System.out.print("超过表长");
				}
				break;
			}
			tail = tail.next;
		}
	}