分类算法中的分割错误

Question

so when I run the following code in Xcode, it works, but gives segmentation fault when I run it in terminal and I'm not sure why.

void Word::arrangeWords(char **&words, int*& pages, int size)
{

char *lowest;
int track;
{
    for (int i=0;i<size;i++)
    {
        lowest=new char[30];
        strcpy(lowest, words[i]);;
        for(int j=i+1;j<size;j++)
        {
            int compResult=strcmp(lowest, words[j]);
            if (compResult>0)
            {
                strcpy(lowest, words[j]);
                track=j;
            }
        }
        std::swap(words[track],words[i]);
        std::swap(pages[track],pages[i]);
        delete [] lowest;
    }
}

}

Thanks in advance

Answer 1

I can't figure out what's causing the segmentation fault but there is a bug in your code. You are not resetting the value of track after the calls to std::swap . I suggest the following changes to the function.

void Word::arrangeWords(char **&words, int*& pages, int size)
{
   for (int i=0;i<size;i++)
   {
      int track = i;
      char lowest[30]; // If you know the size of the array to be 30,
                       // just create an array. Why use new char[30]?
      strcpy(lowest, words[i]);;
      for(int j=i+1;j<size;j++)
      {
         int compResult=strcmp(lowest, words[j]);
         if (compResult>0)
         {
            strcpy(lowest, words[j]);
            track=j;
         }
      }
      if ( track > i )
      {
         std::swap(words[track],words[i]);
         std::swap(pages[track],pages[i]);
      }
   }
}