链表的逆放(又称反转)
链表的逆置(又称反转)
链表的逆置常作为应届生面试题,主要考察求职者对链表的理解,还有思维能力。逆置的思路主要是保存几个临时的指针变量,其实好多面试题都可以通过保存临时变量的方式来解决。
C++代码如下:
#include "stdafx.h" struct ListNode { int m_nData; ListNode* m_pNext; }; ListNode* ReverseList(ListNode *pHead) { ListNode* pReversedHead = NULL; ListNode* pNode = pHead; ListNode* pPrev = NULL; while(NULL != pNode) { ListNode* pNext = pNode->m_pNext; if (NULL == pNext) pReversedHead = pNode; pNode->m_pNext = pPrev; pPrev = pNode; pNode = pNext; } return pReversedHead; } int _tmain(int argc, _TCHAR* argv[]) { int len = 10; ListNode *pHead = new ListNode; pHead->m_nData = 10; pHead->m_pNext = NULL; ListNode *pPrev = pHead; for (int i=0; i<len; i++) { ListNode *p = new ListNode; p->m_nData = i; p->m_pNext = NULL; if (NULL != pPrev) { pPrev->m_pNext = p; } pPrev = p; } ListNode *pReversedHead = ReverseList(pHead); return 0; }