分离链接法的删除操作函数

习题5.11 分离链接法的删除操作函数   (20分)

试实现分离链接法的删除操作函数。

函数接口定义：

bool Delete( HashTable H, ElementType Key );

其中HashTable是分离链接散列表，定义如下：

typedef struct LNode *PtrToLNode;struct LNode {    ElementType Data;    PtrToLNode Next;};typedef PtrToLNode Position;typedef PtrToLNode List;typedef struct TblNode *HashTable; /* 散列表类型 */struct TblNode {   /* 散列表结点定义 */    int TableSize; /* 表的最大长度 */    List Heads;    /* 指向链表头结点的数组 */};

函数Delete应根据裁判定义的散列函数Hash( Key, H->TableSize )从散列表H中查到Key的位置并删除之，然后输

出一行文字：Key is deleted from list Heads[i]，其中Key是传入的被删除的关键词，i是Key所在的链表的编

号；最后返回true。如果Key不存在，则返回false。

裁判测试程序样例：

#include <stdio.h>#include <string.h>#define KEYLENGTH 15                   /* 关键词字符串的最大长度 */typedef char ElementType[KEYLENGTH+1]; /* 关键词类型用字符串 */typedef int Index;                     /* 散列地址类型 */typedef enum {false, true} bool;typedef struct LNode *PtrToLNode;struct LNode {    ElementType Data;    PtrToLNode Next;};typedef PtrToLNode Position;typedef PtrToLNode List;typedef struct TblNode *HashTable; /* 散列表类型 */struct TblNode {   /* 散列表结点定义 */    int TableSize; /* 表的最大长度 */    List Heads;    /* 指向链表头结点的数组 */};Index Hash( ElementType Key, int TableSize ){    return (Key[0]-'a')%TableSize;}HashTable BuildTable(); /* 裁判实现，细节不表 */bool Delete( HashTable H, ElementType Key );int main(){    HashTable H;    ElementType Key;    H = BuildTable();     scanf("%s", Key);    if (Delete(H, Key) == false)        printf("ERROR: %s is not found\n", Key);    if (Delete(H, Key) == true)        printf("Are you kidding me?\n");    return 0;}/* 你的代码将被嵌在这里 */

输入样例1：散列表如下图

able

输出样例1：

able is deleted from list Heads[0]

输入样例2：散列表如样例1图

date

输出样例2：

ERROR: date is not found

#include <stdio.h>#include <stdlib.h>#include <string.h>#define N 10#define KEYLENGTH 15typedef char ElementType[KEYLENGTH+1];typedef int Index;typedef enum{false,true}bool;typedef struct LNode* PtrToLNode;struct LNode{ElementType Data;PtrToLNode Next;};typedef PtrToLNode Position;typedef PtrToLNode List;typedef struct TblNode* HashTable;struct TblNode{int TableSize;List Heads;};Index Hash(ElementType Key, int TableSize){return (Key[0]-'a')%TableSize;}HashTable BuildTable();void insert(HashTable H, ElementType Element);HashTable InitializeTable(int Tablesize);Position Find(ElementType key, HashTable H);bool Delete(HashTable H, ElementType Key);int main(){HashTable H;ElementType Key;H = BuildTable();scanf("%s", Key);if(Delete(H, Key)==false)printf("ERROR: %s is out found\n", Key);elseprintf("Are you kidding me?\n");return 0;}HashTable InitializeTable(int Tablesize){HashTable hashTable;int i;hashTable=(HashTable)malloc(sizeof(struct TblNode));hashTable->TableSize=N;hashTable->Heads=(List)malloc(sizeof(struct LNode)*N);for(i=0;i<N;i++){hashTable->Heads[i].Next=NULL;}return hashTable;}Position Find(ElementType key, HashTable H){      int i = Hash(key, H->TableSize);  List p = H->Heads[i].Next; while (p != NULL && strcmp(p->Data, key)) {          p=p->Next;    }    return p;}  void Insert(ElementType key, HashTable H){List P;    if (Find(key, H) == NULL) {          int i = Hash(key, H->TableSize);          List L = (List)malloc(sizeof(struct LNode));  strcpy(L->Data, key);P = &H->Heads[i];        L->Next = P->Next;  //头插法        P->Next = L;      }else{printf("Already exist!\n");}}  bool Delete(HashTable H, ElementType Key){Position p=NULL,q=NULL;int i = Hash(Key, H->TableSize);p=Find(Key, H);if (p==NULL)return false;else{if(p != NULL && !strcmp(p->Data, Key)){ //p->Data == KeyH->Heads[i].Next=p->Next;free(p);}else{while (p != NULL && strcmp(p->Data, Key)){ //p->Data != Keyq=p;p=p->Next;}if(p->Next==NULL){q->Next=NULL;free(p);}else{q->Next=p->Next;free(p);}}printf("%s is deleted from list Heads[%d]\n", Key, i);return true;}}HashTable BuildTable(){HashTable H;Position P;H = InitializeTable(N);Insert("zero", H);Insert("very", H);Insert("day", H);Insert("able", H);Insert("bye", H);Insert("key", H);printf("I am Here!\n");    P = Find("able", H);      printf("%s\n",P->Data);return H;}