单链表反序

typedef struct node *linklist;

//revese linklist

linklist reverselinklist1(linklist l) {

      linklist current, p;

      if(l == NULL) {

           return NULL;

      }

      current = l -> next;

      while(current -> next != NULL) {

           p = current -> next;

           current -> next = p -> next;

           p -> next = l -> next;

           l -> next = p;

      }

      return l;

}

 

linklist reverselinklist2(linklist l) {

      linklist current, p;

      if(l == NULL) {

           return NULL;

      }

      current = l -> next;

      while(current -> next != NULL) {

           p = current -> next;

           l -> next = p;

           current -> next = p -> next;

           p -> next = current;

      }

}

 

linklist reverselinklist3(linklist l) {

      linklist newlist, temp;

      newlist = (linklist)malloc(sizeof(struct node));

      if(l == NULL || newlist == NULL) {

           return NULL;

      }

      newlist -> data = l -> data;

      newlist -> next = NULL;

      while(l -> next != NULL) {

           temp = newlist -> next;

           newlist -> next = l -> next;

           l -> next = l -> next -> next;

           newlist -> next -> next = temp;

      }

      free(l);

      return newlist;

}