Help with Binary Search

i need help finishing the tail end of this program, i'm not sure how to finish the Binary Search at the end of the program, can someone help please!!

Code:

---

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <iostream.h>
#include <fstream.h>
#include <ctype.h>
#include <iomanip.h>


class wordanddef
{
public:
        char* word;
    char* def;

};


int loaddata(char *fn, wordanddef wadptr[]);
void sortdata(int numlines, wordanddef wadptr[]);
int findword(int numlines, wordanddef pwordanddef, char *wrd)

int main(void)
{
char fname[100], sword[20], origword[20];
int linecnt, fwordnum, ccnt;
wordanddef pwordanddef[400];

        strcpy(fname, "defs.dat");

        linecnt=loaddata(fname, pwordanddef);
        if(linecnt==-1)
        {
        cout<<"File could not be opened";
        system("Pause");
                exit(1);
        }

    sortdata(linecnt, pwordanddef);

        while(strcmp (sword, "")!=0)
        {
                cout<<"\nEnter the word to search for, or hit enter to exit:  ";
                cin.getline(sword, 20);
                strcpy(origword, sword);

                fwordnum=findword(linecnt, pwordanddef, sword);

                if(fwordnum==-1)
            cout<<"\nNot found.\n";
                else
                {
                        cout<<"\nWord found.\n";
                        cout<<"Original Word As Typed: "<<origword<<"\n";
                        cout<<"Word: "<<pwordanddef[fwordnum].word<<"\n";
                        cout<<"Definition: "<<pwordanddef[fwordnum].def<<"\n";

                }
        }

}

int loaddata(char *fn, wordanddef wadptr[])
{
ifstream file;
char line[80];
int cnt=0;

char tmpWord[50];
char tmpDef[500];


        file.open(fn);

        if(file.fail())
        return -1;

    while (file.peek() != EOF)
    {
      file >> tmpWord;
      file >> ws;
      file.getline(tmpDef, 999);

      wadptr[cnt].word = new char[1+strlen(tmpWord)];
      strcpy(wadptr[cnt].word, tmpWord);

      wadptr[cnt].def = new char[1+strlen(tmpDef)];
      strcpy(wadptr[cnt].def, tmpDef);
      cnt++;
      }
        file.close();

        return cnt;
}

void sortdata(int numlines, wordanddef wadptr[])
{
int swap, sortcnt;
wordanddef twadptr;

        swap=1;
        while(swap)
        {
                swap=0;
        sortcnt=0;
                while(sortcnt<numlines-1)
                {
                        if(strcmp(wadptr[sortcnt].word, wadptr[sortcnt+1].word)>0)
                        {
                                twadptr=wadptr[sortcnt];
                                wadptr[sortcnt]=wadptr[sortcnt+1];
                                wadptr[sortcnt+1]=twadptr;
                                swap=1;
                        }
                        sortcnt++;
                }
        }
}

int findword(int numlines, wordanddef pwordanddef, char *wrd)
{
int bottom = 0;
int top = numlines - 1;
int middle;

while (bottom < top)
{
 middle = (top + bottom)/2;
 if (wrd < pwordanddef[middle])
  top = middle +1;
 else
    bottom = middle;
}
 if (wrd == pwordanddef[bottom])

---

well, for an array of ints it'd be:

Code:

---

int bsearch(int value, int array[], int count) {
 int bottom = 0,
    top = count-1,
    middle;
 while (bottom <= top) {
  middle =(top + bottom)/2;
  if(value == array[middle]) {
  return middle;
  } else if (value < array[middle]) {
  top = middle - 1;
  } else {
  bottom = middle + 1;
  }
  }
 return -1;
 }

---

>> if (wrd < pwordanddef[middle])

why are you comparing a char* to a struct?

This is 100% personal preference but I prefer

Code:

---

middle =(top - bottom)/2 + bottom;

---

over

Code:

---

middle =(top + bottom)/2;

---

Reasoning: it is possible for an array to be of such a large size that the value of top + bottom to overflow INT_MAX (think if the item you were looking for was the second to last item in the arry).
Using top - bottom elimates that possiblity.