Inverted single linked list of C + + algorithm

Title: Define a function, enter the head node of a linked list, reverse the list and output the head node of the inverted list, the linked list node is defined as:

struct ListNode

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int m_nvalue;

listnode* M_pnext;

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Algorithm ideas:

Linked list 1-->2-->3-->4-->5

Establishes a Pprev node, and is an empty node; pprev = null; then establish a node Pnode = Phead; Then build a third node Pnext = pnode->m_pnext;

Pnext: Used to save a node behind a pnode, preventing the list from breaking in the middle, and then traversing Pprev and Pnode down:

Look at the code:

listnode* reverselist (listnode* head) {listnode* pnode = head; listnode* Pprev = Null;while (pnode! = NULL) {listnode* Pnext = pnode->m_pnext;//Save the value of the next node Pnode->m_pnext = pprev;// The next node of the current Pnode points to Pprevpprev = pnode;//at this point the pprev moves backwards to Pnodepnode = pnext;//at this point and pnode moves backwards, pointing to the pnext that was just saved;} return Pprev;//return Preversedhead;}

Full code:

ReverseList.cpp: Defines the entry point of the console application. #include "stdafx.h" #include <iostream>using namespace std;struct listnode{int m_nvalue; listnode* M_pnext; ListNode () {}listnode (int i): M_nvalue (i), M_pnext (NULL) {}};void addtotail (listnode* phead, int value) {listnode* pnew = New ListNode ();p new->m_nvalue = Value;pnew->m_pnext = null;if (Phead = = NULL) {phead = pnew;} else{listnode* Pnode = Phead;while (pnode->m_pnext!=null) {pnode = Pnode->m_pnext;} Pnode->m_pnext = Pnew;}} void Print (listnode* head) {listnode* Pnode = head;while (pnode!=null) {cout<<pnode->m_nvalue<<endl; Pnode = Pnode->m_pnext;}} listnode* reverselist (listnode* head) {listnode* pnode = head; listnode* Pprev = Null;while (pnode! = NULL) {listnode* Pnext = Pnode->m_pnext;pnode->m_pnext = PPrev;pPrev = PNode;p Node = Pnext;} return Pprev;//return Preversedhead;} int _tmain (int argc, _tchar* argv[]) {/*listnode* head = new ListNode (1); listnode* Node1 = new ListNode (2); listnode* Node2 = new ListnodE (3); listnode* node3 = new ListNode (4); listnode* node4 = new ListNode (5); head->m_pnext = Node1;node1->m_pnext = Node2;node2->m_pnext = Node3;node3-&gt ; m_pnext = Node4;node4->m_pnext = null;*/listnode* pNode1 = new ListNode (1);//print (PNODE1); Addtotail (pnode1,2); Addtotail (pnode1,3); Addtotail (pnode1,4); Addtotail (pnode1,5);cout<< "invert before:" <<endl; Print (PNODE1);//print (head); listnode* Pnode = reverselist (pNode1);cout<< "after reversal" <<endl; Print (Pnode); GetChar (); return 0;}

Code can run the test pass!

Inverted single linked list of C + + algorithm