链表翻转。给出一个链表和一个数k，比如链表1→2→3→4→5→6，k=2，则翻转后2→1→4→3→6→5，若k=3,翻转后3→2→1→6→5→4，若k=4，翻转后4→3→2→1→5→6，用程序实现

最新推荐文章于 2024-04-07 09:03:34 发布

yingsun

最新推荐文章于 2024-04-07 09:03:34 发布

阅读量6.4k

点赞数 2

CC 4.0 BY-SA版权

分类专栏：算法

本文链接：https://blog.youkuaiyun.com/zzran/article/details/15184749

算法专栏收录该内容

46 篇文章

订阅专栏

本文介绍了一种链表中长度为k的段摘除、翻转并重新连接的算法，通过具体实现展示了如何使用C++进行链表操作。

题目中最重要的就是学会一种方法，就是把链表中长度为k的一段从链表中摘除，翻转之后在将其衔接回链表。这是主要的思绪，以下按照此思路给出程序：

#include<iostream>
using namespace std;

typedef struct LNode {
	int m_nValue;
	struct LNode* m_pNext;
}LNode;

LNode* reverseList(LNode* pHead) {
	if (NULL == pHead || NULL == pHead->m_pNext)
		return pHead;
	LNode* pNode;
	LNode* pNewHead = NULL;
	while (pHead) {
		pNode = pHead;
		pHead = pHead->m_pNext;
		pNode->m_pNext = pNewHead;
		pNewHead = pNode;
	}
	return pNewHead;
}

LNode* getLastNode(LNode* pHead) {
	while (NULL != pHead->m_pNext)
		pHead = pHead->m_pNext;
	return pHead;
}

LNode* swapListByK(LNode* pHead, int k) {
	if (k <= 1)
		return pHead;
	int pos;
	LNode* pNode = pHead;
	LNode* pNewHead;
	LNode* pNextNode;
	LNode* pLastNode = NULL;;
	pHead = NULL;
	while (pNode) {
		pos = 0;
		pNewHead = pNode;
		while (pNode && pos < k - 1) {
			pNode = pNode->m_pNext;
			pos++;
		}
		if (pNode) {
			pNextNode = pNode->m_pNext;
			pNode->m_pNext = NULL;
			if (NULL != pLastNode) {
				pLastNode->m_pNext = NULL;
			}
			pNewHead = reverseList(pNewHead);
			if (NULL == pHead) {
				pHead = pNewHead;
			} else {
				pLastNode->m_pNext = pNewHead;
			}
			pNode = getLastNode(pNewHead);
			pNode->m_pNext = pNextNode;
			pLastNode = pNode;
			pNode = pNextNode;
		} else {
			break;
		}
	}
	return pHead;
}

void printList(LNode* pHead) {
	LNode* pNode = pHead;
	while (pNode) {
		cout << pNode->m_nValue << " ";
		pNode = pNode->m_pNext;
	}
	cout << endl;
}

LNode* createList(int* arr, int length) {
	LNode* pHead = NULL;
	LNode* pTemp, *pNode;
	for (int i = 0; i < length; i++) {
		pNode = (LNode*)malloc(sizeof(LNode));
		pNode->m_nValue = arr[i];
		pNode->m_pNext = NULL;
		if (NULL == pHead)
			pHead = pNode;
		else
			pTemp->m_pNext = pNode;
		pTemp = pNode;
	}
	return pHead;
}

void destroyList(LNode* pHead) {
	LNode* pNode;
	while (pHead) {
		pNode = pHead;
		pHead = pHead->m_pNext;
		free(pNode);
	}
}

int main(int argc, char* argv[]) {
	int arr[] = {1, 2, 3, 4, 5, 6, 7, 8, 9};
	int length = sizeof(arr) / sizeof(arr[0]);
	LNode* pHead = createList(arr, length);
	pHead = swapListByK(pHead, 2);
	printList(pHead);
	destroyList(pHead);
	cin.get();
	return 0;
}