面试题5：从尾到头打印链表
题目链接：http://ac.jobdu.com/problem.php?pid=1511
思路：修改链表的指向。
使用三个指针head pRes pNext
保存pRes = head
保存head = pNext->next
修改pNext->next = pRes
更新pRes = pNext
更新pNext = head
code:
1 #include <cstdio> 2 using namespace std; 3 struct node 4 { 5 int nValue; 6 struct node* next; 7 }; 8 node* reserveNodeList(node* head) 9 { 10 if (head == NULL) return NULL; 11 node* pRes = head; 12 node* pNext = head->next; 13 head->next = NULL; 14 while (pNext != NULL) 15 { 16 head = pNext->next; 17 pNext->next = pRes; 18 pRes = pNext; 19 pNext = head; 20 } 21 head = pRes; 22 return head; 23 } 24 int main() 25 { 26 int n; 27 scanf("%d", &n); 28 if (n == -1) return 0; 29 node* head = new node; 30 head->nValue = n; 31 head->next = NULL; 32 node* p = head; 33 while (scanf("%d", &n), n != -1) 34 { 35 node* pCurrent = new node; 36 p->next = pCurrent; 37 pCurrent->nValue = n; 38 pCurrent->next = NULL; 39 p = p->next; 40 } 41 head = reserveNodeList(head); 42 while (head != NULL) 43 { 44 printf("%d\n", head->nValue); 45 head = head->next; 46 } 47 return 0; 48 }
