My first ever school project written in c. it was supposed to be a ticketmaster-like vending system.

teatro.c

#include<stdio.h>
#include<conio.h>
#include<ctype.h>
#include<string.h>

char teatro[25][80],fil,resp;
int i=0,j=0,sw=0,as,cont;

void main()
{
strcpy(teatro[0]  , "   ___________________________________________________________________ ");
strcpy(teatro[1]  , "  |           |_____|                           |_____|               |");
strcpy(teatro[2]  , "  |                                                                   |");
strcpy(teatro[3]  , "  | L[ ][ ][ ][ ][ ][ ][ ][ ][ ][ ]    [ ][ ][ ][ ][ ][ ][ ][ ][ ][ ] |");
strcpy(teatro[4]  , "  | K[ ][ ][ ][ ][ ][ ][ ][ ][ ][ ]    [ ][ ][ ][ ][ ][ ][ ][ ][ ][ ] |");
strcpy(teatro[5]  , "  | J[ ][ ][ ][ ][ ][ ][ ][ ][ ][ ]    [ ][ ][ ][ ][ ][ ][ ][ ][ ][ ] |");
strcpy(teatro[6]  , "  | I[ ][ ][ ][ ][ ][ ][ ][ ][ ][ ]    [ ][ ][ ][ ][ ][ ][ ][ ][ ][ ] |");
strcpy(teatro[7]  , "  | H[ ][ ][ ][ ][ ][ ][ ][ ][ ][ ]    [ ][ ][ ][ ][ ][ ][ ][ ][ ][ ] |");
strcpy(teatro[8]  , "  | G[ ][ ][ ][ ][ ][ ][ ][ ][ ][ ]    [ ][ ][ ][ ][ ][ ][ ][ ][ ][ ] |");
strcpy(teatro[9]  , "  | F[ ][ ][ ][ ][ ][ ][ ][ ][ ][ ]    [ ][ ][ ][ ][ ][ ][ ][ ][ ][ ] |");
strcpy(teatro[10] , "  | E[ ][ ][ ][ ][ ][ ][ ][ ][ ][ ]    [ ][ ][ ][ ][ ][ ][ ][ ][ ][ ] |");
strcpy(teatro[11] , "  | D[ ][ ][ ][ ][ ][ ][ ][ ][ ][ ]    [ ][ ][ ][ ][ ][ ][ ][ ][ ][ ] |");
strcpy(teatro[12] , "  | C[ ][ ][ ][ ][ ][ ][ ][ ][ ][ ]    [ ][ ][ ][ ][ ][ ][ ][ ][ ][ ] |");
strcpy(teatro[13] , "  | B[ ][ ][ ][ ][ ][ ][ ][ ][ ][ ]    [ ][ ][ ][ ][ ][ ][ ][ ][ ][ ] |");
strcpy(teatro[14] , "  | A[ ][ ][ ][ ][ ][ ][ ][ ][ ][ ]    [ ][ ][ ][ ][ ][ ][ ][ ][ ][ ] |");
strcpy(teatro[15] , "  |   1  2  3  4  5  6  7  8  9 10     11 12 13 14 15 16 17 18 19 20  |");
strcpy(teatro[16] , "  |  _______________________________________________________________  |");
strcpy(teatro[17] , "  | |                                                               | |");
strcpy(teatro[18] , "  | |                                                               | |");
strcpy(teatro[19] , "  | |                                                               | |");
strcpy(teatro[20] , "  | |                                                               | |");
strcpy(teatro[21] , "  | |_______________________________________________________________| |");
strcpy(teatro[22] , "  |                                                                   |");
strcpy(teatro[23] , "  |___________________________________________________________________| ");

do{
 //clrscr();
 printf ("\n");
 cont=0;
 j=0;
 i=0;
 do{
  puts(teatro[cont]);
  cont++;
 }while(cont<24);
 printf("\n\nCompra de boletos:");
 printf("\nIngrese la fila: ");
 do{
  do{
   sw=0;
   fil=getche();
   sw=isalpha(fil);
   fflush(stdin);
   if(sw==0)
    printf("\nTiene que ser una letra vuelve a ingresar: ");
  }while(sw==0);
  i=0;
  if ((fil=='a') || (fil=='A'))
   i=14;
  else if ((fil=='b') || (fil=='B'))
   i=13;
  else if ((fil=='c')  || (fil=='C'))
   i=12;
  else if ((fil=='d')  || (fil=='D'))
   i=11;
  else if ((fil=='e') || (fil=='E'))
   i=10;
  else if ((fil=='f') || (fil=='F'))
   i=9;
  else if ((fil=='g') || (fil=='G'))
   i=8;
  else if ((fil=='h') || (fil=='H'))
   i=7;
  else if ((fil=='i') || (fil=='I'))
   i=6;
  else if ((fil=='j') || (fil=='J'))
   i=5;
  else if ((fil=='k') || (fil=='K'))
   i=4;
  else if ((fil=='l') || (fil=='L'))
   i=3;
  if (i==0)
   printf("\nFila inexistente vuelve a ingresar: ");
 }while(i==0);
 printf("\n\nAsiento: ");
 do{
  do{
   do{
    scanf("%d",&as);
    if ((as<1) && (as>20))
     printf("\nAsiento invalida, vuelve a ingresar: ");
   }while(as<1 && as>20);
   j=0;
   if (as>0 && as<12)
    j=3+(as*3);
   if (as>10 &&  as<21)
    j=9+(as*3);
   if(j==0){
    //textcolor(4);
    printf("Tiene que ser una butaca existente vuelve a ingresar: ");
    }
  }while(j==0);
  if (teatro[i][j]=='X')
   printf("\nLo sentimos ese asiento esta ocupado, vuelva a seleccionar: ");
 }while (teatro[i][j]=='X');
 teatro[i][j]='X';
 printf("\nDesea otro boleto(s/n)?");
 resp=getche();
}while(resp=='s');
getch();
}