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(***********************************************************************)
(* *)
(* Objective Caml *)
(* *)
(* Pierre Weis, projet Cristal, INRIA Rocquencourt *)
(* *)
(* Copyright 2001 Institut National de Recherche en Informatique et *)
(* en Automatique. All rights reserved. This file is distributed *)
(* only by permission. *)
(* *)
(***********************************************************************)
(* This program solves the famous game ``Le solitaire'', using a
trivial brute force algorithm.
No graphics involved: results are just printed out as ascii
characters! *)
type peg = | Out | Empty | Peg;;
let board = [|
[| Out; Out; Out; Out; Out; Out; Out; Out; Out|];
[| Out; Out; Out; Peg; Peg; Peg; Out; Out; Out|];
[| Out; Out; Out; Peg; Peg; Peg; Out; Out; Out|];
[| Out; Peg; Peg; Peg; Peg; Peg; Peg; Peg; Out|];
[| Out; Peg; Peg; Peg; Empty; Peg; Peg; Peg; Out|];
[| Out; Peg; Peg; Peg; Peg; Peg; Peg; Peg; Out|];
[| Out; Out; Out; Peg; Peg; Peg; Out; Out; Out|];
[| Out; Out; Out; Peg; Peg; Peg; Out; Out; Out|];
[| Out; Out; Out; Out; Out; Out; Out; Out; Out|]
|];;
let print_peg = function
| Out -> print_string "."
| Empty -> print_string " "
| Peg -> print_string "$";;
let print_board board =
for i = 0 to 8 do
for j = 0 to 8 do
print_peg board.(i).(j)
done;
print_newline ()
done;;
type direction = { dx : int; dy : int };;
let dir =
[| {dx = 0; dy = 1}; {dx = 1; dy = 0};
{dx = 0; dy = -1}; {dx = -1; dy = 0} |];;
type move = { x1 : int; y1 : int; x2 : int; y2 : int };;
let moves = Array.create 31 {x1 = 0; y1 = 0; x2 = 0; y2 = 0};;
let counter = ref 0;;
exception Found;;
let rec solve m =
counter := !counter + 1;
if m = 31 then
begin match board.(4).(4) with | Peg -> true | _ -> false end
else
try
if !counter mod 500 = 0 then begin
print_int !counter; print_newline ()
end;
for i = 1 to 7 do
for j = 1 to 7 do
match board.(i).(j) with
| Peg ->
for k = 0 to 3 do
let d1 = dir.(k).dx in
let d2 = dir.(k).dy in
let i1 = i + d1 in
let i2 = i1 + d1 in
let j1 = j + d2 in
let j2 = j1 + d2 in
match board.(i1).(j1) with
| Peg ->
begin match board.(i2).(j2) with
| Empty ->
board.(i).(j) <- Empty;
board.(i1).(j1) <- Empty;
board.(i2).(j2) <- Peg;
if solve (m + 1) then begin
moves.(m) <- { x1 = i; y1 = j; x2 = i2; y2 = j2 };
raise Found
end;
board.(i).(j) <- Peg;
board.(i1).(j1) <- Peg;
board.(i2).(j2) <- Empty
| _ -> ()
end
| _ -> ()
done
| _ -> ()
done
done;
false
with Found -> true;;
let solve_solitaire () =
if solve 0 then (print_string "\n"; print_board board);;
if !Sys.interactive then () else solve_solitaire ();;
|
