全文檢索索引模型演算法實現

全文檢索索引是一種將檔案中所有文本與檢索項匹配的文字資料檢索方法。全文檢索索引系統是按照全文檢索索引理論建立起來的用於提供全文檢索索引服務的軟體系統。

#include <stdlib.h>#include <string.h>#include <stdio.h>//Status是函數的類型,其值是函數結果狀態碼typedef int Status;#define INT_MAX 32767#define LINESIZE 80//設一行字元數為80#define MAXKEYLEN 26//關鍵字的長度#define MAXNUM 100//統計單詞的最大數typedef struct{  char *ch;  //關鍵字int  num;  //關鍵字的長度char *info;//關鍵字有關資訊}KeysType;     //關鍵字類型typedef enum{LEAF,BRANCH} NodeKind;//結點種類：{葉子，分支}typedef struct DLTNode{char symbol;struct DLTNode *next;     //指向兄弟結點的指標NodeKind kind;            //結點標誌union{struct DLTNode *first;//分支結點的孩子鏈指標struct {int idx;          //葉子結點的count數組下標指標KeysType infoptr;};};}DLTNode,*DLTree;   //雙鏈樹類型char line[LINESIZE];//用於緩衝文章中每行的字串struct{int times;KeysType info;}count[MAXNUM];int NUM=0;//記錄整個文章的單詞總數char ch1[17][100]={"a","an","the","them","there","here","they","are","that","this","those","what","which","why","then","and","these"};void InitTree(DLTree &root){//初始化鍵樹root=new DLTNode;root->next =NULL;root->first=NULL;}//InitTreeStatus Insert_DLTree(DLTree &root,KeysType K,int &n){//指標root所指雙鏈樹中已含n個關鍵字，若不存在和K相同的關鍵字，//則將關鍵字K插入到雙鏈樹中相應位置，樹中關鍵字個數n增1且返回TRUE；..//否則不再插入返回FALSEDLTree p=root->first,f=root,pre,s;int j=0;    while (p && j<K.num ){//在鍵樹中進行尋找        pre=NULL;while (p && p->symbol <K.ch [j]){//尋找和K.ch[j]相同的結點pre=p;p=p->next ;}if (p && p->symbol ==K.ch[j]){f=p;p=p->first ;j++;}//找到後進入鍵樹的下一層，即尋找和K.ch[j+1]相同的結點else{//沒有找到和K.ch[j]相同的結點，插入K.ch[j]s=new DLTNode;s->kind =BRANCH;s->symbol =K.ch [j++];if (pre) pre->next =s;else f->first =s;s->next =p;s->first =NULL;p=s;break;}//else}//while    if (p&&j==K.num && p->first&&p->first ->kind ==LEAF) return FALSE;else{//鍵樹中已存在相同首碼的單詞，插入由剩餘字元構成的單支樹while (j<=K.num ){s=new DLTNode;s->next =NULL;if (p){s->next =p->next ;p->first =s;p=s;}else {f->first =s;p=s;}if(j<K.num ){s->kind =BRANCH;s->symbol =K.ch [j++];s->first =NULL;}else{s->symbol ='$';s->kind =LEAF;n++;s->idx =n;s->infoptr.ch =count[s->idx ].info.ch =K.ch ;s->infoptr.info =count[s->idx ].info.info =K.info ;s->infoptr.num =count[s->idx ].info.num=K.num ;count[s->idx ].times=0;j++;}}//whilereturn TRUE;}//else}//Insert_DLTreevoid CreatDLTree(DLTree &T,KeysType *key,int &n){//建立鍵樹模型for (int i=0;i<=16;i++){key[i].ch=ch1[i];        key[i].info=NULL;key[i].num =strlen(key[i].ch );}key[0].info ="indefinite article.";//akey[1].info ="indefinite articles.";//ankey[2].info ="definite article.";//the    key[3].info ="personal pronoun";//them    key[4].info ="adv. of place and direction";//there    key[5].info ="to this point or place";//here    key[6].info ="pronoun";//they    key[7].info ="v.i. joining subject & predicate";//are    key[8].info ="adj. & pron.";//that    key[9].info ="adj. & pron.";//this    key[10].info ="adj. & pron.";//those    key[11].info ="adj. & pron.,asking for a selection from an indefinite number";//what    key[12].info ="adj. & pron.,asking for a selection from two or a group";//which    key[13].info ="adj. & int.,for what reason,with what purpose";//why    key[14].info ="adv.,at what time";//then    key[15].info ="conj.,connecting words";//and     key[16].info ="adj. & pron.";//these    for(i=0;i<=16;i++)      Insert_DLTree(T,key[i],n);//建立鍵樹模型}//CreatDLTreeStatus Search_DLTree(DLTree rt,int j,int &k){//若line中從第j個字元起長度為k的子串和指標rt所指向雙鏈樹中單詞相同，//則數組count中相應分量增1，並返回TRUE，否則返回FALSEDLTree p;int found;k=0;found=FALSE;p=rt->first ;//p指向雙鏈樹中的第一棵子樹的樹根    while (p && !found){while (p && p->symbol <line[j+k]) p=p->next ;if (!p||p->symbol >line[j+k]) break;//在鍵樹的第k+1層上匹配失敗else{//繼續匹配p=p->first ;k++;if (p->kind ==LEAF){//找到一個單詞if (!(line[j+k]>='a'&&line[j+k]<='z')||(line[j+k]>='A'&&line[j+k]<='Z' )){count[p->idx ].times++;//統計數組對應元素加1found=TRUE;}//若鍵樹中含有"commit"，文本行中為commit則為找到，若為committing則為沒找到}//if}//else}//whilereturn found;}//Search_DLTreevoid setmatch(DLTree root,char *line,FILE *f){//統計以root為根指標的鍵樹中，各關鍵字在本文本串line中重複出現的次數，//並將其累加到統計數組count中去unsigned i=0;int k;//若尋找成功，返回的k為所尋找的關鍵字長度while (fgets(line,LINESIZE,f)!=NULL){cout<<line;        i=0;while (i<=strlen(line)){//LINESIZE){if (!Search_DLTree(root,i,k)) {if (((line[i]>='a' && line[i]<='z')||(line[i]>='A'&&line[i]<='Z')||(line[i]>='0'&&line[i]<='9')) &&!((line[i+1]>='a'&&line[i+1]<='z')||(line[i+1]>='A'&&line[i+1]<='Z')||(line[i+1]>='0'&&line[i+1]<='9')))NUM++;//單詞總數加1    i++;  //若尋找不成功，則從下一個字元開始尋找}//if    else { i+=k;     //尋找成功，繼續在文本串中的第i+k-1個字元開始尋找NUM++;}//else}//while}//while}//setmatchvoid Input(FILE *&f){char fname[30];cout<<"please input the file name:";cin>>fname;                     //輸入檔案名稱if ((f=fopen(fname,"r"))==NULL){//輸入錯誤檔案名稱, 無法開啟cout<<"Can NOT open the file!"<<endl;exit(1);}}//Inputvoid output(int n){cout<<endl;for(int i=1;i<=n;i++)if (count[i].times){cout<<count[i].info.ch<<" : ";if(count[i].info.info) cout<<count[i].info.info<<endl;cout<<float(count[i].times)/float(NUM)<<" in the sentence."<<endl;}//輸出文章中含有鍵樹中的關鍵字及有關解釋，出現頻率。即：該關鍵字出現次數/文章單詞總數 cout<<endl;}