Issue with mergesort

Hi everybody, this program I'm writing is supposed to collect comic books from a file, sort them, then print them. I'm having trouble with my mergesort functions. Heres the declaration and initial call followed by the functions themselves:

Struct Comic

Code:

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struct comic
{
      char title[100];
      char issue[100];
      int issuenum;
      //struct comic *next;
};

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Declarations in Main

Code:

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                          struct comic *thecomics;
                          struct comic *temp;

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Initial Call

Code:

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                            tempcnt = 1;
                            cnt = count +1;
                            do
                            {
                                if(strcmp(thecomics[count].title, thecomics[cnt].title) == 0)
                                {
                                    temp[0] = thecomics[count];
                                    temp[tempcnt] = thecomics[cnt];
                                    tempcnt++;
                                }
                                cnt++;
                            }while(cnt < numcomics);
                            system("pause");
                            mergesort(&temp, tempcnt);
                   
                            cnt = 0;
                            printf("&#37;s\n", temp[0].title);
                            while(cnt <= tempcnt)
                            {
                                      printf("\t%d. %s\n", temp[cnt].issuenum, temp[cnt].issue);
                                      cnt++;
                            }

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Merge Function

Code:

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void merge(struct comic **comicsc, struct comic **leftc, int leftlen, struct comic **rightc, int rightlen)
{
    int comicsnum = 0;
        int leftnum = 0;
        int rightnum = 0;
        int righttst, lefttst;

    // As long as both arrays have more integers, keep merging
        while(leftnum < leftlen && rightnum < rightlen)
        {
        // If the smallest remaining integer in the left half is smaller than
        // the smallest remaining integer in the right half, put the integer
        // from the left half into the final array first
        //righttst = &rightc[rightnum]->issuenum;
        //lefttst = &leftc[leftnum]->issuenum;
                if(&leftc[leftnum]->issuenum <= &rightc[rightnum]->issuenum)
                {
                        *comicsc[comicsnum] = *leftc[leftnum];
                        comicsnum++;
                        leftnum++;
                }
                // Otherwise, go with the right half
                else
                {
                        *comicsc[comicsnum] = *rightc[rightnum];
                        comicsnum++;
                        rightnum++;
                }
        }
       
        // If there aren't any integers left in the right half, that means there
    // must still be some in the left half. Copy the remaining integers from the
    // left half of the array.
        if(rightnum >= rightlen)
        {
                while(leftnum < leftlen)
                {
                        *comicsc[comicsnum] = *leftc[leftnum];
                        comicsnum++;
                        leftnum++;
                }
        }
        // Otherwise, there are still integers in the right half, so copy those
        else
        {
                while(rightnum < rightlen)
                {
                        *comicsc[comicsnum] = *rightc[rightnum];
                        comicsnum++;
                        rightnum++;
                }
        }
}//End merge

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Mergesort Function

Code:

---

void mergesort(struct comic **comics, int len)
{
    struct comic *left;
    struct comic *right;
    int ct;
   
   
    if(len <= 1)
    {
            return;
    }
    system("pause");
    left = (struct comic*)calloc(len/2, sizeof(struct comic));
    for(ct = 0; ct < len/2; ct++)
    {
          left[ct] = *comics[ct];
    }
    mergesort(&left, len/2);
   
    right = (struct comic*)calloc(len - len/2, sizeof(struct comic));
        for(ct = len/2; ct<len; ct++)
        {
                  right[ct - len/2] = *comics[ct];
        }
        mergesort(&right, len - len/2);
       
        merge(&comics, &left, len/2, &right, len-len/2);
       
        free(left);
        free(right);
}//End mergesort

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Whats going on is there is an error code poping when my program reaches the mergesort call. The program runs fine before it hits that. Anyone see what's going on?

Use (*comics)[ct] instead of *comics[ct] -- the compiler treats this as an array of pointers, not a pointer to an array. (Of course, you'll have to do that everywhere.)

You're comparing the addresses of the issuenum variables:

Code:

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                if(&leftc[leftnum]->issuenum <= &rightc[rightnum]->issuenum)

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That's probably not what you intended to do.