建立词索引表（数据结构，串的应用）

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

#define MaxBookNum 1000                           //假设只对1000本书建索引表
#define MaxKeyNum 2500                            //索引表的最大容量
#define MaxLineLen 500                            //书目串的最大长度
#define MaxWordNum 10                             //词表的最大容量

typedef struct{                                  
char *item[MaxKeyNum];                         //字符串的数组
int last;                                                //词表的长度 
}WordListType;                                    //词表类型（顺序表）      

typedef struct LNode{                             //存放书号的链表
int data[3];
struct LNode *next;
}LNode, *LinkList;

typedef struct{                                  //存放关键词的串 
char *ch;
int length;                                  
}HString;

typedef struct{
HString *key;                      
LinkList bnolist;
}IdxTermType;                                   //索引项类型    

typedef struct{
IdxTermType item[MaxKeyNum + 1];
int last;
}IdxListType;                                  //索引表类型（有序表）

char *buf;                          //书目串缓冲区
WordListType wdlist;                           //词表
int i;                                         //无重复的关键字个数
int b;                                         //保留i的前一次变换的值
int v;
char *com[10] = {"and","a","an","the","a","an","to","of"};

IdxListType *InitIdxList(IdxListType *idxlist)         
//初始化操作，置索引表idxlist为空表，且在idxlist.item[0]设一空串。
{
idxlist = (IdxListType *)malloc(sizeof(IdxListType));
if(idxlist == NULL)
{
   printf("ERROR――1!");
   exit(-1);
}
idxlist->item[0].key = (HString *)malloc(sizeof(HString));
idxlist->item[0].bnolist = (LinkList)malloc(sizeof(LNode));
idxlist->item[0].key->ch = NULL;
idxlist->item[0].key->length = 0;
//idxlist->item[0].bnolist->data[3];
idxlist->item[0].bnolist->next = NULL;
idxlist->last = 0;
return idxlist;
}