单链表固定长度翻转

/*********************************************************** * Copyright (C), 2012-2013, Cgema Tech. Co., Ltd. * FileName : test.c * Author : Cgema * Version : 1.0  * Date : 2013.9.13 * Description : 单链表的翻转  * 原链表长度不知，可能是奇数也可能是偶数 * 若原链表为：h->1->2->3->4->5->6->7，则： * k=2时，将链表翻转为h->2->1->4->3->6->5->7 * k=3时，将链表翻转为h->3->2->1->6->5->4->7 * k=4时，将链表翻转为h->4->3->2->1->5->6->7 * 若原链表为：h->1->2->3->4->5->6->7->8，则： * k=4时，将链表翻转为h->4->3->2->1->8->7->6->5 * Source : 美团网2013笔试题***********************************************************/#include<stdio.h>#include<stdlib.h>#define k 3#define length 8int main(){typedef struct node {int num;struct node *next;}*List,Node;int i,n = 0;Node *p,*q,*s,*w;List head = (Node *)malloc(sizeof(Node));head->next = NULL;q = head;for(i=0; i<length; i++)//create linklist with tail{p = (Node *)malloc(sizeof(Node));p->num = i+1;p->next = q->next;q->next = p;q = p;printf("p->num=%d\n",p->num);}  printf("linklist data init success!\n");w = head;q = p = head->next;while(p){n++;if(n == k)//opposite linklist operate{s = q->next;w->next = p->next;p->next = NULL;p = w->next;while(q){q->next = w->next;w->next = q;q = s;if(s)s = s->next;}q = p;if(q)s = q->next;w = head->next;while(w->next != p)w = w->next;n = 0;  printf("opposite linklist operate.\n");}else p = p->next;}if(n != 0)printf("最后一组%d不够%d个结点，不可翻转！\n",n,k);else printf("全部翻转完毕！\n",n);p = head->next;//free linklist node q = head;while(p){printf("p->num=%d\n",p->num);free(q);q = p;p = p->next;}  return 0;}