大家好呀，本博客目的在于记录暑假学习打卡，后续会整理成一个专栏，主要打算在暑假学习完数据结构，因此会发一些相关的数据结构实现的博客和一些刷的题，个人学习使用，也希望大家多多支持，有不足之处也请指出，谢谢大家。

一，力扣21.合并有序链表

. - 力扣（LeetCode）

简单题，定义新的头节点分别遍历两个链表

/*** Definition for singly-linked list.* public class ListNode {*     int val;*     ListNode next;*     ListNode() {}*     ListNode(int val) { this.val = val; }*     ListNode(int val, ListNode next) { this.val = val; this.next = next; }* }*/
class Solution {public ListNode mergeTwoLists(ListNode list1, ListNode list2) {ListNode head=new ListNode(-1);ListNode tail=head;ListNode headA=list1;ListNode headB=list2;while(headA!=null&&headB!=null){if(headA.val>headB.val){tail.next=headB;headB=headB.next;tail=tail.next;}else{tail.next=headA;headA=headA.next;tail=tail.next;}}if(headA!=null){tail.next=headA;}if(headB!=null){tail.next=headB;}return head.next;}
}

二，牛客CM11，链表分割

链表分割_牛客题霸_牛客网

import java.util.*;/*
public class ListNode {int val;ListNode next = null;ListNode(int val) {this.val = val;}
}*/
public class Partition {public ListNode partition(ListNode pHead, int x) {ListNode as = null;ListNode bs = null;ListNode ae = as;ListNode be = ae;ListNode cur = pHead;while (cur != null) {if (cur.val < x) {if (as == null) {as = ae = cur;} else {ae.next = cur;ae = ae.next;}} else {if (bs == null) {bs = be = cur;}else{be.next = cur;be = be.next;}}cur = cur.next;}if (as == null) {return bs;}ae.next = bs;if (bs != null)be.next = null;return as;}
}

特别注意！最后大于x的链表要是存在那么最后的节点next指针一定要置空！否则可能成环

三，牛客OR36，判断回文链表

链表的回文结构_牛客题霸_牛客网

思路1.先找出链表中间节点

       2.把中间节点之后的链表倒置

       3.分别从前往后和从后往前判断val值是否相等

import java.util.*;/*
public class ListNode {int val;ListNode next = null;ListNode(int val) {this.val = val;}
}*/
public class PalindromeList {public boolean chkPalindrome(ListNode A) {if (A == null)return true;ListNode fast = A;ListNode slow = A;while (fast != null && fast.next != null) {fast = fast.next.next;slow = slow.next;}//找中间节点ListNode cur = slow.next;while (cur != null) {ListNode curN = cur.next;cur.next = slow;slow = cur;cur = curN;}//倒置slow之后节点while (A != slow) {if (slow.val != A.val) {return false;}if (A.next == slow) {return true;}slow = slow.next;A = A.next;}return true;}
}

四，力扣160相交链表

. - 力扣（LeetCode）

思路：

1.求出链表长度和差值

2.较长链表先走长度的差值步，然后两个链表一起走，相遇即为交点

/*** Definition for singly-linked list.* public class ListNode {*     int val;*     ListNode next;*     ListNode(int x) {*         val = x;*         next = null;*     }* }*/
public class Solution {public ListNode getIntersectionNode(ListNode headA, ListNode headB) {ListNode pl=headA;ListNode ps=headB;int lenA=0,lenB=0;while(pl!=null){pl=pl.next;lenA++;}while(ps!=null){ps=ps.next;lenB++;}pl=headA;ps=headB;int len=lenA-lenB;if(len<0){pl=headB;ps=headA;len=lenB-lenA;}while(len>0){pl=pl.next; len--;}while(pl!=ps){pl=pl.next;ps=ps.next;}return pl;}
}

博客就到这里，感谢大家观看