   Q U E E N S     -  Platform: MVS/TSO


   This program is a resolution of the eight chess queens problem,
that is, in a chessboard you must put 8 queens in a way that every
queen cannot hit any other queen.


   In this distribution file (QUEENS.ZIP) there is:

QUEENS.OBJ               executable for MVS/TSO mainframe, in obj form
QUEENS.HIL               Hilmas source of this file
README.TXT               this help file 
LINKEDIT.JCL             job example to install QUEENS


OBJ installation:

- Create in MVS a sequential file, for example 'MYUSER.PROGRAM.OBJ'
  with RECFM=FB and LRECL=80, for example of 1 cylinder.

- SEND obj module from PC to MVS in this file in BINARY form, with your 
  3270 emulation; the most important thing is a binary transfer (therefore 
  without ASCII CRLF) in a file with record length of 80 bytes.
  Use this PC command (in a PC with IBM/PCOMM 4.1 3270 emulation installed):

     SEND QUEENS.OBJ 'MYUSER.PROGRAM.OBJ'

- Prepare a Job to Linkedit transferred obj in a load library (possibily
  in Linklist): use LINKEDIT.JCL as example: fit this JCL to your needs
  changing library names

- Submit linkedit job to create load module; output library must be a
  load library used by TSO users (i.e. in  //JOBLIB ) or a linklist library
  (in this case, you must refresh linklist with F LLA,REFRESH command)



Program instruction:

   This program is a generalization of the classic problem: you can
have a solution for every chessboard size from 4 to 12; and at the same
time this programming problem is a classical example of recursivity.
We thanks to Niklaus Wirth for the algorithm.

   To test the program write in your TSO/ISPF session:

      TSO  QUEENS

   The program starts and ask you the size of the chessboard; then,
for every output line a solution is showed: the first number is the row
where to put a queen in the first column; the second number is the row 
where to put the second queen in the second column, and so on.


