/* Druver program to test above function */
int main()
{
struct node *start = NULL;
/* The constructed linked list is:
1->2->3->4->5 */
// push(&start, 7);
// push(&start, 6);
// push(&start, 5);
// push(&start, 4);
// push(&start, 3);
push(&start, 2);
push(&start, 1);
printf("\n Linked list before calling pairWiseSwap() ");
printList(start);
pairWiseSwap(&start);
printf("\n Linked list after calling pairWiseSwap() ");
printList(start);
getchar();
return 0;
}
struct node *pairWiseSwap(struct node* head)
{
if (head == NULL || head->next == NULL)
return head;
struct node* remaing = head->next->next;
struct node* newhead = head->next;
newhead->next = head;
head->next = pairWiseSwap(remaing);
return newhead;
}
//方法二: 递归
void pairWiseSwap(struct node *head)
{
if (NULL == head || NULL == head->next)
{
return ;
}
head->data ^= head->next->data;
head->next->data ^= head->data;
head->data ^= head->next->data;
pairWiseSwap(head->next->next);
}
int main()
{
struct node *start = NULL;
/* The constructed linked list is:
1->2->3->4->5->6->7 */
push(&start, 7);
push(&start, 6);
push(&start, 5);
push(&start, 4);
push(&start, 3);
push(&start, 2);
push(&start, 1);
printf("\n Linked list before calling pairWiseSwap() ");
printList(start);
start = pairWiseSwap(start); // NOTE THIS CHANGE
printf("\n Linked list after calling pairWiseSwap() ");
printList(start);
return 0;
}