Segmentation fault when reading from file

<div>The aim of the program is to read contents from 2 files and store it in struct variables.(This is actually a part of another program which stimulates pass2 of two pass assembler)

This code works fine.

#include
#include
#include
struct optbl
{
char opco[10];
int value;
}o_tbl[100];
struct symtbl
{
char sym[10];
int addr;
}s_tbl[100];
int count=0,n=0;
main()
{
int i;
char a[100];
FILE *fp2;
fp2=fopen("OP_TBL.TXT","r");
if(fp2)
printf("Opened");
while(1)
{
fscanf(fp2,"%s",a);
if(feof(fp2))
break;
strcpy(o_tbl[count].opco,a);
fscanf(fp2,"%s",a);
if(feof(fp2))
break;
o_tbl[count++].value=atoi(a);
}
for(i=0;i