Adding words to a char *[] in C - c

Question

I have a program that reads the words of two files (the first a wordlist, and the second an ebook from the Gutenberg project ) into two char *arrays.
I am trying to add all the unique words from the second char *array that don't appear in
the first char *array into a third char *array then print them.
This program adds the correct words, but is adding them more than once.
The error occurs in findOdds().
Note when I use a non-binary search method this program works correctly, but takes a long time.
What is the problem with my program? I apologize for my English.
#include <stdio.h>
#include <stdlib.h> /* for malloc() */
#include <ctype.h>
#include <string.h>
#define MAXCHAR 24
#define MAXLINES 150000
int add2array(FILE *fp, char *lineptr[]);
int findOdds(char *lineptr[], char *lineptr1[], int nlines, int nlines1);
int binsearch1(char *val, char *lineptr[], int nlines);
char *lineptr2[MAXLINES]; /* The unique words not in the word list */
int main(int argc, char *argv[])
{
FILE *my_stream, *my_stream1;
char *lineptr[MAXLINES], *lineptr1[MAXLINES];
int i, nlines, nlines1, nlines2;
/* Load the wordlist. */
my_stream = fopen("words.txt","r");
if(my_stream == NULL) {
printf("error: Couldn't open file\n");
return 2;
} else {
nlines = add2array(my_stream, lineptr);
fclose(my_stream);
}
if(nlines==-1) {
printf("error: Epic Failure to copy words to char *lineptr[]\n");
return -1;
}
/* Load the ebook. */
my_stream1 = fopen("horsemanship.txt","r");
if(my_stream1 == NULL) {
printf("error: Couldn't open file\n");
return 2;
} else {
nlines1 = add2array(my_stream1, lineptr1);
fclose(my_stream1);
}
if(nlines1==-1) {
printf("error: Epic Failure to copy words to char *lineptr[]\n");
return -1;
}
/* Find and print the unique words from the ebook not in the wordlist */
nlines2 = findOdds(lineptr, lineptr1, nlines, nlines1);
for(i=0; i<nlines2; i++)
printf("%s\n",lineptr2[i]);
return 0;
}
/* add2array: read the words from the file into char *lineptr[] */
int add2array(FILE *fp, char *lineptr[])
{
int nlines=0, c=0, pos=0;
char temp[MAXCHAR];
char *p;
while((c = getc(fp)) != EOF) {
if(isalpha(c))
temp[pos++] = tolower(c);
else if(!isalpha(c)) {
temp[pos] = '\0';
pos = 0;
if(isalpha(temp[0])){
if((p = malloc(sizeof(temp)))==NULL)
return -1;
strcpy(p, temp);
lineptr[nlines++] = p;
}
}
}
return nlines;
}
/* Add the unique words from lineptr1 not in lineptr to lineptr2 */
int findOdds(char *lineptr[], char *lineptr1[], int nlines, int nlines1)
{
char *p;
char temp[MAXCHAR];
int i, nlines2=0;
for(i=0; i<nlines1; i++) {
if(binsearch1(lineptr1[i], lineptr, nlines)==-1) {
if(binsearch1(lineptr1[i], lineptr2, nlines2)==-1) {
if((p = malloc(sizeof(temp)))==NULL)
return -1;
strcpy(p, lineptr1[i]);
lineptr2[nlines2++] = p;
}
}
}
return nlines2;
}
int binsearch1(char *val, char *lineptr[], int nlines)
{
int pos;
int start = 0;
int end = nlines-1;
int cond = 0;
while(start <= end){
pos=(start + end)/2;
if((cond = strcmp(lineptr[pos],val)) == 0)
return pos;
else if(cond < 0)
start = pos+1;
else
end = pos-1;
}
return -1;
}

Answer 1

Arrays must be sorted if you want to use binary search, as stated above by n.m.
in main() ...
shellsort1(lineptr1, nlines1);
/* Find and print the unique words from the ebook not in the wordlist */
nlines2 = findOdds(lineptr, lineptr1, nlines, nlines1);
...
int shellsort1(char *v[], int n)
{
int gap, i, j;
char temp[MAXCHAR];
char *p;
for(gap=n/2; gap>0; gap/=2)
for(i=gap; i<n; i++)
for(j=i-gap; j>=0 && strcmp(v[j],v[j+gap])>0; j-=gap) {
if((p = malloc(sizeof(temp)))==NULL)
return -1;
p = v[j];
v[j] = v[j+gap];
v[j+gap] = p;
}
return 0;
}