1、单链表--Java操作

我就是我 2022-07-16 23:52 208阅读 0赞

单链表Java操作：

package algorithm.array_linked;
    
    import java.util.Stack;
    
    /**
     * 链表简单操作
     * @author baolibin
     * 1、Linked_01 构造方法
     * 2、addEle 头部增加节点
     * 3、addEnd 尾部增加节点
     * 4、deleteLinked 删除指定节点
     * 5、updateLinked 修改指定节点
     * 6、getLinkedText 查询指定节点
     * 7、print 有头单链表遍历、无头单链表遍历、单链表倒序遍历
     * 8、reversal 链表翻转
     * 9、sortLinked 链表排序
     * 10、getMiddle 返回中间元素
     * 11、getLoop 判断链表是否有环
     * 12、raversalR 链表翻转递归
     */
    public class _01_linked {
    	public static void main(String[] args) {
    		//头结点
    		Linked_01 head = new Linked_01(null,null);
    		Linked_01 head2 = new Linked_01(null,null);
    		
    		//头部插入
    		Linked_01 insert_1 = new Linked_01("one",null);
    		Linked_01 insert_2 = new Linked_01("two",null);
    		Linked_01 insert_3 = new Linked_01("three",null);
    		Linked_01 insert_4 = new Linked_01("four",null);
    		head.addEle(head, insert_1);
    		head.addEle(head, insert_2);
    		head.addEle(head, insert_3);
    		head.addEle(head, insert_4);
    //		head.print(head);
    		head.reversal(head);
    //		head.print(head);
    		
    		//尾部插入
    		Linked_01 insert2_1 = new Linked_01("one",null);
    		Linked_01 insert2_2 = new Linked_01("two",null);
    		Linked_01 insert2_3 = new Linked_01("three",null);
    		Linked_01 insert2_4 = new Linked_01("four",null);
    		Linked_01 insert2_5 = new Linked_01("five",null);
    //		Linked_01 insert2_6 = new Linked_01("six",null);
    		head2.addEnd(head2, insert2_1);
    		head2.addEnd(head2, insert2_2);
    		head2.addEnd(head2, insert2_3);
    		head2.addEnd(head2, insert2_4);
    		head2.addEnd(head2, insert2_5);
    //		head2.addEnd(head2, insert2_6);
    		head2.print(head2);
    		//反转链表
    //		head2.reversal(head2);
    //		head2.print(head2);
    		//删除指定节点
    //		head2.deleteLinked(head2,4);
    //		head2.print(head2);
    		//修改指定节点的值
    //		head2.updateLinked(head2, 1, "update_value");
    //		head2.print(head2);
    		//查询指定节点的值
    //		String str=head2.getLinkedText(head2, 3);
    //		System.out.println(str);
    //		head2.print(head2);
    		//链表排序
    //		head2.sortLinked(head2);
    //		head2.print(head2);
    		//返回中间元素
    //		String getMiddle=head2.getMiddle(head2);
    //		System.out.println(getMiddle);
    //		head2.print(head2);
    		//判断链表是否有环
    //		System.out.println(head2.getLoop(head2));
    		Linked_01 loop1 = new Linked_01("one",null);
    		Linked_01 loop2 = new Linked_01("two",null);
    		Linked_01 loop3 = new Linked_01("three",null);
    		Linked_01 loop4 = new Linked_01("four",null);
    		Linked_01 loop5 = new Linked_01("five",null);
    		loop1.next=loop2;
    		loop2.next=loop3;
    		loop3.next=loop4;
    		loop4.next=loop5;
    		loop5.next=loop1;
    //		System.out.println(loop1.getLoop(loop1));
    		//递归反转
    		Linked_01 newLinked=head2.next;
    //		newLinked=newLinked.raversalR(newLinked);
    //		newLinked.print(newLinked,true);
    		//倒序输出
    		newLinked.print(newLinked, 1);
    	}
    }
    
    class Linked_01{
    	String text;
    	Linked_01 next;
    	/**
    	 * 构造方法
    	 * @param text 节点内容
    	 * @param linked_01  当前节点所指向的节点
    	 */
    	public Linked_01(String text,Linked_01 next) {
    		this.text=text;
    		this.next=next;
    	}
    	/**
    	 * 头部插入
    	 * @param head
    	 * @param insert
    	 */
    	public void addEle(Linked_01 head,Linked_01 insert){
    		insert.next=head.next;
    		head.next=insert;
    	}
    	/**
    	 * 尾部插入
    	 */
    	public void addEnd(Linked_01 head,Linked_01 insert){
    		Linked_01 out=head;
    		while(out.next!=null){
    			out=out.next;
    		}
    		out.next=insert;
    	}
    	/**
    	 * 删除指定节点
    	 * @param head 链表的头指针
    	 * @param index 删除第几个节点
    	 */
    	public void deleteLinked(Linked_01 head,int index){
    		Linked_01 out=head;
    		while (out.next!=null) {
    			--index;
    			if(index==0){
    				break;
    			}
    			out=out.next;
    		}
    		if(out.next!=null){
    			out.next=out.next.next;
    		}
    	}
    	/**
    	 * 修改指定节点内容
    	 * @param head 链表的头指针
    	 * @param index 修改第几个节点
    	 * @param value 修改的值
    	 */
    	public void updateLinked(Linked_01 head,int index,String value){
    		Linked_01 out=head;
    		while (out.next!=null) {
    			--index;
    			if(index==0){
    				break;
    			}
    			out=out.next;
    		}
    		if(out.next!=null){
    			out.next.text=value;
    		}
    	}
    	/**
    	 * 查询链表
    	 * @param head 操作的链表头指针
    	 * @param index 返回第几个节点的值
    	 * @return
    	 */
    	public String getLinkedText(Linked_01 head,int index){
    		String tmp="不存在";
    		Linked_01 out=head;
    		while (out.next!=null) {
    			--index;
    			if(index==0){
    				break;
    			}
    			out=out.next;
    		}
    		if(out.next!=null){
    			return out.next.text;
    		}
    		return tmp;
    	}
    	/**
    	 * 遍历链表
    	 * @param head 遍历链表的头指针
    	 */
    	public void print(Linked_01 head){
    		Linked_01 out=head;
    		while (out.next!=null) {
    			System.out.print(out.next.text+"、");
    			out=out.next;
    		}
    		System.out.println("\n");
    	}
    	/**
    	 *  链表无头结点遍历
    	 * @param head
    	 * @param flag
    	 */
    	public void print(Linked_01 head,boolean flag){
    		if(flag){
    			while (head!=null) {
    				System.out.print(head.text+"、");
    				head=head.next;
    			}
    		}
    		System.out.println("\n");
    	}
    	/**
    	 * 链表倒序遍历
    	 */
    	public void print(Linked_01 head,int flag){
    		Stack<String> stack = new Stack<String>();
    		if(flag==1){
    			while (head!=null) {
    				stack.push(head.text);
    				head=head.next;
    			}
    //			for (String str : stack) {
    //				System.out.print(str+"、");
    //			}
    			while (!stack.isEmpty()) {
    				System.out.print(stack.pop()+"、");
    			}
    			System.out.println("\n");
    		}
    	}
    	/**
    	 * 链表反转
    	 * 1、新建节点insert指向当前节点current的下一个节点
    	 * 2、当前节点current的下下节点赋值给当前节点current的下一个节点
    	 * 3、头结点head的下一个节点赋值给新建节点insert的下一个节点
    	 * 4、头结点head下一个节点指向insert节点
    	 */
    	public void reversal(Linked_01 head){
    		Linked_01 current=head.next;
    		Linked_01 insert=null;
    		while (current.next.next!=null) {
    			insert=current.next; //第一步
    			current.next=current.next.next; //第二步
    			insert.next=head.next; //第三步
    			head.next=insert; //第四步
    		}
    		insert=current.next;
    		current.next=null;
    		insert.next=head.next;
    		head.next=insert;
    	}
    	/**
    	 * 简单选择排序
    	 * 链表排序
    	 */
    	public void sortLinked(Linked_01 head){
    		Linked_01 current=head.next; //当前值待替换的节点
    		Linked_01 slip=null; //滑动节点
    		Linked_01 select; //最小值节点
    		String tmp;
    		while(current.next!=null){
    			select=null;
    			tmp=current.text;
    			slip=current.next;
    			while (slip!=null) {
    				if(slip.text.compareTo(tmp)<0){
    					tmp=slip.text;
    					select=slip;
    				}
    				slip=slip.next;
    			}
    			if(tmp!=null&&select!=null){
    				select.text=current.text;
    				current.text=tmp;
    			}
    			current=current.next;
    		}
    	}
    	/**
    	 * 返回链表中间元素
    	 */
    	@SuppressWarnings("null")
    	public String getMiddle(Linked_01 head){
    		if(head==null&&head.next==null){
    			return "空链表";
    		}
    		Linked_01 first=head;
    		Linked_01 second=head;
    		while(first.next!=null&&second.next!=null&&second.next.next!=null){
    			first=first.next;
    			second=second.next.next;
    		}
    		if(second.next!=null){ //当链表节点个数是奇数时成立
    			return first.next.text;
    		}
    		return first.text;
    	}
    	/**
    	 * 判断链表是否有环
    	 * @param head
    	 * @return
    	 */
    	public int getLoop(Linked_01 head){
    		Linked_01 slow=head;
    		Linked_01 high=head;
    		while(slow.next!=null&&high.next!=null&&high.next.next!=null){
    			slow=slow.next;
    			high=high.next.next;
    			if(slow==high){
    				return 1;
    			}
    		}
    		return 0;
    	}
    	/**
    	 * 链表反转递归
    	 */
    	public Linked_01 raversalR(Linked_01 head){
    		if(head==null||head.next==null||head.next.next==null){
    			return head;
    		}
    		Linked_01 rHead=raversalR(head.next);
    		head.next.next=head;
    		head.next=null;
    		return rHead;
    	}
    }