由於while循環導致的分段錯誤錯誤

Question

我正在實現一個小型搜索引擎。該信息是從文件中獲取的，並且包含該詞的所有搜索都會返回。問題是當我在while循環中運行搜索函數時，一個分段錯誤的錯誤，但當我運行它沒有一個while循環時，它運行順利..我已經重新檢查了代碼不少次，但無法找到任何問題。任何幫助，將不勝感激。

//searches individual words which are given to it.array has some data in it 
int search_word(string word,string array) 
{ 
    int counter=0; 
    size_t found; 
    int i=0; 
    for (i=array.find(word,0);i!=string::npos;i=array.find(word,i)) 
    { 
     counter+=1; 
     i++; 
    } 
    return counter; 
} 



//this is sorting(descending) the linked list of results and storing it in an array 
void Rank() 
{ 
    struct results *go; 
    go=head; 
    int array[54]; 
    int l=0; 
    while (go->next!=0) 
    { 
     array[l]=go->number; 
     array1[l]=go->result; 
     go=go->next; 
     ++l; 
    } 
    array[l]=go->number; 
    array1[l]=go->result; 
    int temp; 
    string temp1; 
    for (int k=0;k<l;k++) 
    { 
     for (int j=(k+1);j<l+1;j++) 
     { 
      if (array[k]<array[j]) 
      { 
      temp=array[k]; 
      array[k]=array[j]; 
      array[j]=temp; 
      temp1=array1[k]; 
      array1[k]=array1[j]; 
      array1[j]=temp1; 
      } 
     }     
    } 
    cout<<"Following results were found"<<endl; 
    for (int a=0;a<l;++a) 
    { 
     cout<<"Result no."<<a<<endl; 
     cout<<array1[a]<<endl; 
     cout<<endl; 
    } 
} 

//main search function     
void search(string array[]) 
{ 
    //words like the,a,he,they,would are low rank words 
    ifstream fin; 
    fin.open("lowRank.txt"); 
    string lowrank; 
    int j=0; 
    while (!fin.eof()) 
    { 
     string buffer; 
     do 
     { 
      getline(fin,buffer); 
      lowrank+=" "; 
      lowrank+=buffer; 
      ++j; 
     } 
     while (!buffer.empty()); 
    } 
    fin.close(); 
    cout<<"Enter a word or phrase"<<endl; 
    //converting the string containing words into seperate strings by tockenisation 
    string setofwords[10]; 
    char phrase[50]; 
    cin.get(phrase,50); 
    int count=0; 
    char *pointer= NULL; 
    pointer=strtok(phrase," "); 
    while (pointer!=NULL) 
    { 
     char *pointer= NULL; 
     setofwords[count]=pointer;  
     pointer=strtok(NULL," "); 
     count+=1; 
     delete [] pointer; 
    }  

    for (int i=0;i<54;i++) 
    { 
     int counter=0;int counter1=0; 
     //searching for all words one by one in the below loop  
     for (int k=0;k<count;k++)  
     {   
      //searching if word is low rank 
      size_t found; 
      found=lowrank.find(setofwords[k]);     
      if (found!=string::npos) 
      { 
       counter=search_word(setofwords[k],array[i]); 
       if (counter>0) 
       {      
        counter1+=1; 
       } 
      } 
      else 
      {           
       counter=search_word(setofwords[k],array[i]); 
       counter1+=counter;     
      }   
     } 
    if (counter1>0) 
    { 
     add_result(array[i],counter1); 
    } 
    } 
    Rank(); 
} 

int main() 
{ 
    //reading the data file and copying it into an a linked list 
    ifstream fin; 
    fin.open("data.txt"); 
    while (!fin.eof()) 
    {  
     string url; 
     string data; 
     getline(fin,url); 
     string buffer; 
     do 
     { 
      getline(fin,buffer);   
      if (!buffer.empty()) 
      { 
       data=buffer; 
      } 
     } 
     while (!buffer.empty()); 
     add_node(url,data); 
    } 
    //copying linked list to an array 
    string array[54]; 
    node *conductor; 
    conductor=root; 
    for (int i=0;i<54;i++) 
    { 
     array[i]=conductor->url+conductor->data; 
     conductor=conductor->next; 
    }     

    fin.close(); 

    while (1) 
    {    


     cout<<"*******************************SEARCH         
     ENGINE********************************"<<endl; 
     cout<<endl; 
     cout<<endl; 
     cout<<endl; 
     cout<<"1.Press 1 to search a word."<<endl; 
     cout<<"5.Press 5 to quit without saving search results"<<endl; 

    int ans; 

     cin>>ans;  
     if (ans==1) 
     {  
      search(array); 
      search(array); 
     } 

     else if (ans==5) 
     { 
      quit_without_saving(); 
     } 
     } 

system("PAUSE"); 
return 0; 
} 

Answer 1

分割故障可能是由於delete []上的指針的使用不是由一個調用返回到new[]：沒有張貼在代碼中的關鍵字new的一個實例，但有一個delete的實例。

Answer 2

你的錯誤是在這行代碼：

char phrase[50]; 
cin.get(phrase,50); 
int count=0; 
char *pointer= NULL; 
pointer=strtok(phrase," "); 
while (pointer!=NULL) 
{ 
    char *pointer= NULL; 
    setofwords[count]=pointer;  
    pointer=strtok(NULL," "); 
    count+=1; 
    delete [] pointer; 
} 

strtok實際上返回您在你通過什麼，在這種情況下phrase指向一個字符。

phrase在堆棧上創建。

因此，您不能致電delete[]就可以了。順便提一下，你也不能在分配的塊的中間調用delete[]，它必須恰好是從new[]調用返回的指針。

順便說一句，如果你需要改變你的代碼，這樣phrase需要知道它在運行時的大小，不要用new[]但短語做成std::vector<char>相反，您可以使用&phrase[0]去它的第一個元素。再次，不需要撥打delete[]