将单链表的每K个节点之间逆序

#include "List.h"
#include <stack>
using namespace std;

Node* resign1(stack<Node*> &nstack, Node* left, Node* right)
{
    Node* cur = nstack.top();
    nstack.pop();
    if(left != nullptr)
        left->next = cur;
    Node* next = nullptr;
    while(!nstack.empty())
    {
        next = nstack.top();
        nstack.pop();
        cur->next = next;
        cur = next;
    }
    cur->next = right;
    return cur;
}

Node* reverseKNode1(Node* head, int k)
{
    if(k < 2)
        return head;
    stack<Node*> nStack;
    Node* newHead = head;
    Node* cur = head;
    Node* pre = nullptr;
    Node* next = nullptr;
    while(cur)
    {
        next = cur->next;
        nStack.push(cur);
        if(nStack.size() == k)
        {
            pre = resign1(nStack, pre, next);
            newHead = newHead == head ? cur : newHead;
        }
        cur = next;
    }
    return newHead;
}

void resign2(Node* left, Node* start, Node* end, Node* right)
{
    Node* pre = start;
    Node* cur = start->next;
    Node* next = nullptr;
    while(cur != right)
    {
        next = cur->next;
        cur->next = pre;
        pre = cur;
        cur = next;
    }
    if(left != nullptr)
        left->next = end;
    start->next = right;
}

Node* reverseKNode2(Node* head, int k)
{
    if(k < 2)
        return head;
    Node* cur = head;
    Node* start = nullptr;
    Node* end   = nullptr;
    Node* pre   = nullptr;
    Node* next  = nullptr;

    int count = 1;
    while(cur)
    {
        next = cur->next;
        if(count == k)
        {
            start = pre == nullptr ? head : pre->next;
            head = pre == nullptr ? cur : head;
            resign2(pre, start, cur, next);
            pre = start;
            count = 0;
        }
        ++count;
        cur = next;
    }
    return head;
}

int main()
{
    Node* pNode0 = new Node(0);
    Node* pNode1 = new Node(1, pNode0);
    Node* pNode2 = new Node(2, pNode1);
    Node* pNode3 = new Node(2, pNode2);
    Node* pNode4 = new Node(1, pNode3);
    Node* pNode5 = new Node(0, pNode4);

    pNode5 = reverseKNode1(pNode5, 3);
    Print(pNode5);

    cout << "============================" << endl;
    pNode5 = reverseKNode2(pNode5, 3);
    Print(pNode5);
}