链表笔记（自用）

 链表定义（来源leetcode）

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode() : val(0), next(nullptr) {}
 *     ListNode(int x) : val(x), next(nullptr) {}
 *     ListNode(int x, ListNode *next) : val(x), next(next) {}
 * };
 */

获取链表长度

int getLength(ListNode* head){
        int count=0;
        while(head){
            count++;
            head=head->next; 
        }
        return count;
    }

删除链表倒数第n个元素

ListNode* removeNthFromEnd(ListNode* head, int n) {
        //虚拟节点，避免头节点为空的现象；
        ListNode* dummy=new ListNode(0,head);     //the first member val to 0, and the second member next to head
        int length=getLength(head);
        ListNode* curr=dummy;
        for(int i=1;i<length-n+1;i++){      //最终将curr定位在待删除元素前一个位置
            curr=curr->next;
        }
        curr->next=curr->next->next;
        ListNode *ans=dummy->next;
        delete dummy;
        return ans;
    }

标签：head,ListNode,val,int,笔记,next,链表,自用
来源： https://blog.csdn.net/M3_0352/article/details/123621558