Question

这是字典的代码。每个节点有26个指针，依此类推。

此代码适用于linux g ++编译器中大约270个字的插入但即使在mac和fedora中的g ++上也显示出分段错误，并在visual studio 2010中显示了一些异常处理错误。如果自动插入超过275个单词，则显示分段错误（ubuntu）。

我并不担心前卫的效率。使用的txt文件包含一行中的英文单词列表。

我只是需要它才能工作。提前谢谢..

#define alphabets 26

#include <iostream>
#include <stdlib.h>
#include <fstream>
#include <string>
#include <string.h>
using namespace std;

class dictionary
{
//// letter node ////
struct node
{
    char letter;
    char * meaning;
    bool completion;
    struct node * pointer[alphabets];
    }* root, * temp;



public:
char * word;    
int length;
int letterPos;
int pointerId;
bool searchFound;
bool inserted;



//// constructor ////
dictionary()
{
    root = new struct node;
    root -> letter = '0';
    root -> meaning = new char[9];
    strcpy(root -> meaning, "rootNode");
    root -> completion = 0; 
    }


//// called from localfunction ////
int insertWord(struct node *& currentNode)
{
    if(currentNode == NULL && letterPos < length)
    {
        //cout << "creating new node" << endl;
        //cout << "in insert function" << " " << word[letterPos] << endl;
        temp = new struct node;
        temp -> letter = word[letterPos];
        currentNode = temp;
        temp -> meaning = NULL;
        //cout << "node address: " << currentNode << endl;
        if(letterPos == length - 1)
        {
            temp -> completion = 1;
            inserted = 1;
            //cout << "inserted" << endl;
            return 0;
            }
        else    
            temp -> completion = 0;

        letterPos++;
        pointerId = word[letterPos] - 'a';
        insertWord(currentNode -> pointer[pointerId]);
        }
    else{

    /*if(letterPos == length - 1)
    {
        cout << "word inserted" << endl;
        currentNode -> completion = 1;
        return 0;
        }*/
    //else
    {
        letterPos++;
        pointerId = word[letterPos] - 'a';
        insertWord(currentNode -> pointer[pointerId]);
        }
    }



    if(letterPos == length)
    {
        //cout << "node letter: " << currentNode -> letter << endl;
        currentNode -> completion = 1;
        //cout << "inseted" << endl;
        inserted = 1;
        return 0;
        }

    /*if(currentNode -> letter == word[letterPos])
        if(letterPos == length - 1)
        {
            cout << "in if condition completion" << endl;
            currentNode -> completion = 1;
            }
    */

    //pointerId = word[letterPos] - 'a';

    }   

//// called from main ////      
int insertIntoDictionary(char * wordNew)
{
    length = strlen(wordNew);
    word = wordNew;
    letterPos = 0;
    inserted = 0;
    pointerId = word[letterPos] - 'a';
    //insertWord(root);
    //cout << "Root: " << root << endl;
    insertWord(root -> pointer[pointerId]);
    }


//// called from localfunction ////
int search(struct node * currentNode)
{
    //cout << "in search function" << " searching " << word[letterPos] << endl;
    if(currentNode == NULL)
    {
        //cout << "end of search" << endl;
        return 0;
        }
    /*if(currentNode == root)
    {
        cout << "search function in root " << endl;
        pointerId = word[letterPos] - 'a';
        search(currentNode -> pointer[pointerId]);
        return 0;
        }*/
    if(word[letterPos] == '\0' && !currentNode -> completion)
    {
        searchFound = 0;
        return 0;
        }
    if(currentNode -> letter == word[letterPos] && word[letterPos] != '\0')
    {
        //cout << "in if condition" << endl;
        if(letterPos == length - 1)
        {
            if(currentNode -> completion)
                searchFound = 1;
            return 0;
            }
        letterPos++;
        pointerId = word[letterPos] - 'a';
        //letterPos++;
        search(currentNode -> pointer[pointerId]);
        /*if(letterPos == length)
        {
            //cout << "word found" << endl;
            searchFound = 1;
            return 0;
            }*/
        }
    /*else
    {
        pointerId = word[letterPos] - 'a';
        //letterPos++;
        search(currentNode -> pointer[pointerId]);
        }
    */

    }


//// called from main ////  
int searchInDictionary(char * wordFind) 
{
    word = wordFind;
    length = strlen(wordFind);
    letterPos = 0;
    searchFound = 0;
    pointerId = word[letterPos] - 'a';
    search(root -> pointer[pointerId]);
    //if(searchFound)

        //cout << "Word found" << endl;
    }


int display1(struct node * currentNode)
{
    int i;
    if(currentNode != NULL)
    {
        //cout << "node letter1: " << currentNode -> letter << endl;
        for(i = 0; i < alphabets; i++)
            display1(currentNode -> pointer[i]);
        }
    }
/*int display()
{
    cout << "display function" << endl;
    //letterPos = 0;
    //pointerId = word[letterPos] - 'a';
    //cout << root -> 
    //display1(root -> pointer[pointerId]);
    cout << "root: " << root << endl;
    pointerId = word[letterPos] - 'a';
    cout << root -> pointer[0] << endl; //-> letter;
    display1(root);
    }*/
};




int autoInsert(dictionary &english)
{
int count = 0;
//dictionary english;
FILE * file = fopen("words2.txt", "r");
char * line;
char ch;
/*while(fgets(line, sizeof line, file) != NULL)
{
    cout << "Inserting: " << line << endl;
    english.insertIntoDictionary(line);
    }*/
line = new char[25];
const char * ptr = &ch;
while( count < 274 && ( ch = fgetc(file) ) != EOF )
{
    if(ch != '\n')
        strcat(line, ptr);
    else
    {
        count++;
        cout << "Inserting: " << line << endl;
        english.insertIntoDictionary(line);
        delete [] line;
        line = new char[25];
        }
    }
return 0;
}


int main()
{
/*dictionary english;
char * word = "apple";
cout << "insert command" << endl;
english.insertIntoDictionary(word);

cout << "search command" << endl;
english.searchInDictionary(word);
*/
system("clear");
dictionary english;
int ch;
char w[100];
start:
cout << "1. insert word\n2. search\n3. auto insert\n4. exit " << endl;
cout << "Enter choice: ";
cin >> ch;
if(ch > 3)
    return 0;
if(ch != 3)
{
    cout << "word: ";
    cin >> w;
    }
switch(ch)
{
    case 1: english.searchInDictionary(w);
        if(english.searchFound)
        {
            cout << "word already exists" << endl;
            break;
            }
        english.insertIntoDictionary(w);
        if(english.inserted)
            cout << "word inserted" << endl;
        break;
    case 2: english.searchInDictionary(w);
        if(english.searchFound)
            cout << "Word found" << endl;
        else
            cout << "Word not found" << endl;
        break;
    case 3: autoInsert(english);
        break;
    default: return 0;
    }
goto start;
return 0;
}

这是完整的代码： http://www.heypasteit.com/clip/10XL

和txt文件链接： http://www.heypasteit.com/clip/10XN

Answer 1

发生这种情况可能是因为在创建新节点时指针[字母]没有被初始化。试试struct node

的这个定义

//// letter node ////
struct node
{
    char letter;
    char * meaning;
    bool completion;
    struct node * pointer[alphabets];
    node()
    {
        for(int i =0; i<alphabets;i++)
        {
            pointer[i]=NULL;
        }
    }
}* root, * temp;

Answer 2

这是函数autoInsert（）;

的改变代码

int autoInsert(dictionary &english)
{
int count = 0;
fstream file("123.txt",ios::in);
char * line = NULL;
char ch;
line = new char[25];
line[0] = '\0';
ch='\0';
char * ptr = &ch;
while( count < 1510 &&  file.getline(line,25,'\n'))
{
    {
        count++;
        cout << "Inserting: " << line << endl;
        english.insertIntoDictionary(line);
        }
    }
    file.close();
return 0;
}

这完全适用于代码块，但显示未处理的异常，内存访问冲突。

适用于g ++ ubuntu，但在Visual Studio中显示分段错误，代码块和mac中的g ++

2 个答案: