题目：单链表取反

#include 
   
     #include 
    
      typedef struct node *list; typedef struct node *position; typedef struct node *ListNode; typedef struct node { int data; position next; }node; static list init_list(void); static void delete_list(list L); static int isempty(list L); static void insert_node(position L,int data); static void delete_node(list L,position P); static position find_last(list L); static position find_value(list L,int data); static position find_pre(list L,position P ); static void print(list L); list init_list(void){ list L = (list)malloc(sizeof(node)); L->next = NULL; return L; } void delete_list(list L){ position P ,next; P = L; do{ next = P->next; free(P); P = next; }while(next != NULL); } int isempty(list L){ return (L->next == NULL); } void insert_node(position P,int data){ position tem ; tem = (position)malloc(sizeof(node)); tem->data = data; tem->next = P->next; P->next = tem; } void delete_node(list L,position P){ position pre ; pre = find_pre( L, P); if(pre != NULL) { pre->next = P->next; free(P); } else { printf("delete_node:p is not in the list!\n"); } } position find_last(list L){ position P; P=L; while(P->next != NULL) { P = P->next; } return P; } position find_value(list L,int data){ position P ; P = L; while(P->next != NULL) { P = P->next; if(P->data == data) return P; } return NULL; } position find_pre(list L,position P ){ position tem ; tem = L; while(tem->next != NULL) { if(tem->next == P) return tem; tem = tem->next; } return NULL; } void print(list L){ position P; if(isempty( L)) { printf("print: L is a null list!\n"); return ; } P = L; while(P->next !=NULL) { P = P->next; printf("print:%p : %d \n",P,P->data); } printf("\n"); } /** * Definition for singly-linked list. * struct ListNode { * int val; * struct ListNode *next; * }; */ ListNode reverseList( ListNode head) { if((head == NULL)||(head->next == NULL) ) return head; ListNode cur= head; ListNode tempt=NULL; while (cur->next!=NULL&& cur!=NULL) { tempt=cur->next; cur->next=tempt->next; tempt->next=head; head=tempt; tempt=cur->next; } return head; } int main() { int a[6]= {1,2,3,4,5,6}; int i=0; list L,L1; L = init_list(); print(L); printf("insert node\n"); for(i=0;i<6;i++) { insert_node( L,a[i]); } print( L); L1 = reverseList(L); print( L1); }