menu driven final progarm

#include<stdio.h>
#include<stdlib.h>
#include<conio.h>
#include<string.h>
int display();
void dispintegration(int);
typedef struct optab
{
    char in[20];//instruction
    int op;//opcode
}optab;
typedef struct instruc
{
    int ad;//address of instruction
    char l[10];//label
    char i[10];//instruction
    char o[10];//operand
    int opcode;//opcode
    char symtab[10];
}instruc;
int main()
{
        optab a[20];
        char fname[20],character;                                                       //TO STORE ALL INSTRUCTIONS AND OPCODES
        int address[20]={0x0},amain[20]={0},h[10],size=0x0,f1;   //TO STORE ADDRESSES OF SYMBOLS IN PROGRAM
        instruc b[30];                                                          //TO STORE PROGRAM
        int ad=0x0,disp=0x0,t=0xaaaa,ch1;                                                   //ADDRESS,NEW ADDRESS,DISPLACEMENT
        int i=0,j=0,nad=0x0,pc=0x0,k,m,c,k1,q,nnad,counter;
        long long int t1;                                              //VARIABLES
        char ch;
        FILE *f;                                                        //FILE POINTER
        int choice,ch7;
        system("COLOR 02");
        printf("\n\n\t\tJAC ASSEMBLER:\n\n");
        f=fopen("opcode.txt","r");                                              //READING OPCODE FILE
        if(f==NULL)
        {
          puts("CAN'T OPEN FILE");
          exit(1);
        }
        else
        {
            while(fscanf(f,"%s\t%x\n",&a[i].in,&a[i].op)!=EOF)
            {
                i++;
            }
        }
        fclose(f);
        printf("ENTER THE FILENAME : ");
        gets(fname);
        f=fopen(fname,"r");
        //READING PROGRAM FILE
        if(f==NULL)
        {
            puts("CAN'T OPEN FILE");
            exit(2);
        }
        else
        {
            while(fscanf(f,"%s\t%s\t%s\n",&b[j].l,&b[j].i,&b[j].o)!=EOF)
            {
                //printf("%s\t%s\t%s\n",b[j].l,b[j].i,b[j].o);
                j++;
            }
        }
        fclose(f);                                                                                                         //PROGRAM FILE READ
        nad=0;
        printf("\nPROGRAM WILL START AT 0000 ADDRESS INITIALLY\n");
        printf("\nDO YOU WANT TO RELOCATE :\n\nPRESS    y/Y FOR YES or ANY OTHER KEY FOR NO : ");                          //RELOCATABLE ADDRESS
        scanf("%c",&ch);
        if(ch=='y'||ch=='Y')
        {
            printf("\nENTER NEW ADDRESS:");
            scanf("%x",&nad);
        }
        system("cls");
        //pass 1
        t=0xaaaa;
        b[0].ad=nad;
        b[0].opcode=0xaaaa;
        pc=nad;
        for(k=1;k<j;k++)
        {
            c=0;
            //address calcultion
            b[k].ad=pc;
            //checking symbol in symbol table
            if(strcmp(b[k].l,"_____"))
            {
                for(i=0;i<j;i++)
                {
                    if(!strcmp(b[i].symtab,b[k].l))
                    {
                        printf("\nERROR\n");
                        exit(3);
                    }
                }
                strcpy(b[k].symtab,b[k].l);
                address[k]=b[k].ad;
            }
            //checking for intruction in optab
            for(m=0;m<37;m++)
            {

                if(!strcmp(b[k].i,a[m].in))
                {
                    c++;
                    b[k].opcode=a[m].op;
                    amain[k]=1;
                    pc=pc+3;
                }

            }
            if(c==0)
            {
                if(!strcmp(b[k].i,"RESB"))
                {
                    q=atoi(b[k].o);
                    b[k].opcode=0xaaaa;
                    pc=pc+q;
                }
                else if(!strcmp(b[k].i,"RESW"))
                {
                    q=atoi(b[k].o);
                    pc=pc+3*q;
                    b[k].opcode=0xaaaa;
                }
                else if(!strcmp(b[k].i,"BYTE"))
                {
                    nnad=strlen(b[k].o);
                    //nnad=nnad-3;
                    pc=pc+nnad;
                    b[k].opcode=atoi(b[k].o);
                }
                else if(!strcmp(b[k].i,"WORD"))
                {
                    pc=pc+3;
                    q=atoi(b[k].o);
                    b[k].opcode=q;
                }
            }
        }//PASS 1 ENDS
        size=(pc-nad)+1;
        printf("\nPASS 1 ENDS:\n\nSIZE CALCULATED IS %x\n\n",size);
        printf("\npress enter to continue:");
        getch();
        system("cls");
        k1=k;
        //pass 2
        k1=k;
        pc=nad;
        for(k=1;k<j-1;k++)
        {
            c=0;
            for(m=0;m<37;m++)
            {
                if(!strcmp(b[k].i,a[m].in))
                {
                    c++;
                    pc=pc+3;
                    break;
                }
            }
            if(c==1)
            {
                disp=0x0;
                for(m=0;m<j;m++)
                {
                    if(!strcmp(b[k].o,b[m].symtab))
                    {
                        disp=address[m];
                    }
                }
                b[k].opcode=(b[k].opcode*0x10000)+disp;
            }
        }//PASS 2 ENDS
        printf("\nPASS 2 ENDS:\n");
        printf("\nDO YOU WANT TO PRINT THE PROGRAM:\n\nPRESS 1 FOR YES AND ANY OTHER KEY FOR NO : ");
        scanf("%d",&ch1);
        printf("\n");
        if(ch1==1)
        {
            for(k=0;k<j;k++)
            {
                printf("%x\t%s\t%s\t%s\t",b[k].ad,b[k].l,b[k].i,b[k].o);
                if(b[k].opcode==0xaaaa)
                {
                    printf("     \n");
                }
                else
                {
                    printf("%x\n",b[k].opcode);
                }
            }
        }
        printf("\npress enter to continue:");
        getch();
        system("cls");
        //writing output
        pc=nad;
        int qq=0;
        printf("\n");
        for(i=0;i<j;i++)
        {
            if(amain[i]==1)
            {
                if(b[i].opcode!=0xaaaa)
                {
                    if(qq%4==0)
                    {
                         printf("\n%x\t",pc);
                    }
                    qq++;
                    printf("%x\t",b[i].opcode);
                    pc=pc+3;
                }
                else
                {
                    printf("x");
                }
            }
        }
        //writing text record
        system("cls");
        counter=0;
        f=fopen("record.txt","w");
        fprintf(f,"H %x %x\n",nad,size);
        for(i=0;i<j;i++)
        {
            if(amain[i]==1)
            {
                counter++;
            }
        }
        if(counter>30)
        {
            if((counter/2)<=30)
            {
                counter=2;
            }
            else if((counter/3)<=30)
            {
                counter=3;
            }
            else if((counter/4)<=30)
            {
                counter=4;
            }
            else if((counter/5)<=30)
            {
                counter=5;
            }
        }
        if(counter>0)
        {
            fprintf(f,"T ");
            for(i=0;i<j;i++)
            {
                if(amain[i]==1)
                {
                    if(b[i].opcode!=0xaaaa)
                    {
                        fprintf(f,"%x  ",b[i].opcode);
                    }
                    if(b[i].opcode==0xaaaa)
                    {
                        fprintf(f,"\n");
                        break;
                    }
                }
            }
            printf("\n");
            counter--;
        }
        for(i=0;i<j;i++)
        {
            if(amain[i]==1)
            {
                f1=address[i];
                break;
            }
        }
        fprintf(f,"\ne %x\n",f1);
        fclose(f);
        printf("PROGRAM ENDS PRESS ANY KEY FOR MORE OPTIONS : ");
        getche();
        system("cls");
        do
        {
            system("cls");
            printf("1. PRESS 1 TO EXIT \n");
            printf("2. PRESS 2 TO KNOW THE SIZE\n");
            printf("3. CREDITS \n");
            printf("4. INSTRUCTION SET \n");
            printf("5. GIVEN PROGRAMME\n");
            printf("6. WHOLE PROGRAMME \n");
            printf("7. ABOUT\n");
            scanf("%d",&choice);
            switch(choice)
            {
                case 1:
                    printf("THE PROGRAMME TERMINATES\n");
                    exit(0);
                case 2:
                    printf("SIZE IS EQUAL TO : %X",size);
                    break;
                case 3:
                    f=fopen("instruction.txt","r");
                    while(!feof(f))
                    {
                        character=fgetc(f);
                        printf("%c",character);
                    }
                    break;
                case 4:
                    for(pc=0;pc<37;pc++)
                    {
                        printf("%s     %x\n",a[pc].in,a[pc].op);
                    }
                    break;
                case 5:
                    printf("GIVEN PROGRAMME \n");
                    for(pc=0;pc<j;pc++)
                    {
                        printf("%s\t%s\t%s\n",b[pc].l,b[pc].i,b[pc].o);
                    }
                    break;
                case 6:
                    printf("WHOLE PROGRAMME\n");
                    for(pc=0;pc<j;pc++)
                    {
                        printf("%x\t%s\t%s\t%s\t",b[pc].ad,b[pc].l,b[pc].i,b[pc].o);
                        if(b[pc].opcode==0xaaaa)
                        {
                            printf("     \n");
                        }
                        else
                        {
                            printf("%x\n",b[pc].opcode);
                        }
                    }
                    break;
                case 7:
                    f=fopen("about.txt","r");
                    while(!feof(f))
                    {
                        character=fgetc(f);
                        printf("%c",character);
                    }
        }
        printf("\n\nenter choice if you want view options again 1:yes ");
        scanf("%d",&ch7);
        system("cls");
    }while(ch7==1);
}