Reverse linked list-finger offer-16

title : Define a function, enter the head node of a linked list, reverse the list and output the head node of the inverted list.

Analysis:

Header-by-head interpolation for reversal

Set 3 pointers: Head node, prev previous node, cur next node

Note: The linked list is empty, or only one node is in the case!

Code:

#include <iostream>using namespace Std;struct listnode{int val; ListNode *next; ListNode (int x): Val (x), Next (nullptr) {}};class solution{public:listnode* reverselist (listnode* phead) {if (Phead = = nullptr | | Phead->next = = nullptr) return phead; ListNode Dummy ( -1);d ummy.next = Phead; ListNode *head = &dummy; listnode* prev = head->next; listnode* cur = prev->next;do{prev->next = Cur->next;cur->next = Head->next;head->next = Cur;cur = prev ->next;} while (cur! = nullptr); return dummy.next;};

Sword refers to the code on the offer book:

Listnode* reverlist (listnode* phead) {    listnode* preversehead =  null;    listnode* pnode = phead;    listnode*  pprev = null;        while (PNode != NULL)     {        ListNode* pNext =  pnode->m_next;                 if (pnext == null)              preversehead = pnode;                   pNode->m_next = pPrev;                   pPrev = pNode;          pnode = pnext;    }        return  preversehead; }

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Reverse linked list-finger offer-16