單鏈表交換相鄰元素

#include <stdio.h>#include <stdlib.h>typedef struct node{struct node* next;int key;} Node;//交換相鄰的元素，如果是交換兩結點的值就很簡單，但是交換結點的話就。。//以下是交換結點。//如 1 2 3 4 5 ==> 2 1 4 3 5Node* swapAdjacent(Node *head1){if(head1==NULL) return head1;Node *q=head1,*pre=NULL;while(q && q->next){Node *p1=q,*p2=q->next;q=p2->next;p1->next=p2->next;p2->next=p1;if (pre == NULL) head1 = p2;else pre->next = p2;pre = p1;}return head1;}//建立列表Node* createList(int *s,int len){int i=0;Node* head=NULL,*tail=NULL;for(i=0;i<len;++i){Node* newNode=(Node*)malloc(sizeof(Node));newNode->key=s[i];newNode->next=NULL;if(tail==NULL){head=tail=newNode;}else{tail->next=newNode;tail=newNode;}}return head;}//列印元素void pr_list(Node* head){while(head){printf("%d ",head->key);head=head->next;}}//釋放void freeList(Node* head){while(head){Node* tmp=head;head=head->next;free(tmp);}printf("\n");}int main(void) {int s[]={1,2,3,4,5,6,7,8,9,10,11};int len=sizeof(s)/sizeof(*s);Node *head=createList(s,len);head=swapAdjacent(head);pr_list(head);freeList(head);return 0;}