链表问题

单向链表的操作

创建链表，逆序链表，合并链表

 

// ConsoleApp.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include <stdlib.h>



typedef struct Node
{
	int   m_data;
	Node* m_pNext;
	Node(int data, Node* pNext) {
		this->m_data = data;
		this->m_pNext = pNext;
	}
}TNODE;


//1,2,3,4,5,6,7
//7,6,5,4,3,2,1
//逆序链表
Node*  ReverseList(Node*  pList)
{
	Node* pHead = pList;
    if (pHead == nullptr)
    {
		return pHead;
    }
	Node*  pPrev = nullptr;
	Node*  pOperator = pHead;
	Node*  pOperatorNext = pOperator->m_pNext;


	while (pOperator) {
		pOperator->m_pNext = pPrev;
		pPrev = pOperator;
		pOperator = pOperatorNext;

		if (pOperator) {
			pOperatorNext = pOperator->m_pNext;
		}

	}
	
	return pPrev;
}




void PrintList(Node* pList) {
	Node* node = pList;
	printf("List= ");
	while (node) {
		printf(" %d ,", node->m_data);
		node = node->m_pNext;
	}
	printf("\n");
}


//逆序链表
void testReverseList()
{
	Node* head = nullptr;
	Node* pPrev = nullptr;

	for (int i = 0; i < 20; i++) {

		Node* node = new Node(i, NULL);
		if (pPrev)
		{
			pPrev->m_pNext = node;
		}
		else {
			head = node;
		}
		pPrev = node;
	}

	PrintList(head);

	Node* reHead = ReverseList(head);
	printf("afterReverse\n");
	PrintList(reHead);


}


Node*  CreateList(int arry[] , int n_size)
{
	Node*  pHead = nullptr;
	Node*  pPrev = nullptr;
 
	for (int i = 0; i < n_size; ++i)
	{
		Node* pNode = new Node(arry[i], NULL);
		if (i == 0)
		{
			pHead = pNode;
		}
		if (pPrev)
		{
			pPrev->m_pNext = pNode;
		}
		pPrev = pNode;
	}

	return pHead;
}



Node*   MergeList(Node*  pList1, Node*  pList2) {
	Node*  pNewList = nullptr;
	if (pList1&& pList2)
	{
		Node*   p1 = pList1;
		Node*   p2 = pList2;
		Node*   pPrev1 = nullptr;
		Node*   pPrev2 = nullptr;

		if (pList1->m_data <= pList1->m_data)
			pNewList = pList1;
		else
			pNewList = pList2;

		int flag = 0;

		//1,3,4,6,9,10
		//5,6,7,8,11,12
		while (true)
		{
			if ( p1->m_data <= p2->m_data)
			{
				if (flag == 2)
				{
					pPrev2->m_pNext = p1;
					flag = 0;
				}
				pPrev1 = p1;
				p1 = p1->m_pNext;
				flag = 1;
				if (p1 == nullptr)
				{
					pPrev1->m_pNext = p2;
					break;
				}
			}
			else {
				if (flag == 1) {
					pPrev1->m_pNext = p2;
					flag = 0;
				}
				pPrev2 = p2;
				p2 = p2->m_pNext;
				flag = 2;
				if (p2 == nullptr)
				{
					pPrev2->m_pNext = p1;
					break;
				}

			}
		}
	}

	return pNewList;
}

//合并2个链表
void testMergeList() {
	int aray1[] = { 1,3,4,6,9,10 };
	int aray2[] = { 2,5,6,7,8,11,12 };

	Node*  pList1 = CreateList(aray1, sizeof(aray1) / sizeof(int));
	Node*  pList2 = CreateList(aray2, sizeof(aray2) / sizeof(int));

	PrintList(pList1);
	PrintList(pList2);

	Node* newList =  MergeList(pList1, pList2);



	PrintList(newList);

}

int main() {

	testMergeList();

	system("pause");
	return 0;
}