Penney's game: Difference between revisions

=={{header|BBC BASIC}}==

<lang bbcbasic>REM >penney

PRINT "*** Penney's Game ***"

REPEAT

PRINT ' "Heads you pick first, tails I pick first."

PRINT "And it is... ";

WAIT 100

ht% = RND(0 - TIME) AND 1

IF ht% THEN

PRINT "heads!"

PROC_player_chooses(player$)

computer$ = FN_optimal(player$)

PRINT "I choose "; computer$; "."

ELSE

PRINT "tails!"

computer$ = FN_random

PRINT "I choose "; computer$; "."

PROC_player_chooses(player$)

ENDIF

PRINT "Starting the game..." ' SPC 5;

sequence$ = ""

winner% = FALSE

REPEAT

WAIT 100

roll% = RND AND 1

IF roll% THEN

sequence$ += "H"

PRINT "H ";

ELSE

PRINT "T ";

sequence$ += "T"

ENDIF

IF RIGHT$(sequence$, 3) = computer$ THEN

PRINT ' "I won!"

winner% = TRUE

ELSE

IF RIGHT$(sequence$, 3) = player$ THEN

PRINT ' "Congratulations! You won."

winner% = TRUE

ENDIF

ENDIF

UNTIL winner%

REPEAT

valid% = FALSE

INPUT "Another game? (Y/N) " another$

IF INSTR("YN", another$) THEN valid% = TRUE

UNTIL valid%

UNTIL another$ = "N"

PRINT "Thank you for playing!"

END

:

DEF PROC_player_chooses(RETURN sequence$)

LOCAL choice$, valid%, i%

REPEAT

valid% = TRUE

PRINT "Enter a sequence of three choices, each of them either H or T:"

INPUT "> " sequence$

IF LEN sequence$ <> 3 THEN valid% = FALSE

IF valid% THEN

FOR i% = 1 TO 3

choice$ = MID$(sequence$, i%, 1)

IF choice$ <> "H" AND choice$ <> "T" THEN valid% = FALSE

NEXT

ENDIF

UNTIL valid%

ENDPROC

:

DEF FN_random

LOCAL sequence$, choice%, i%

sequence$ = ""

FOR i% = 1 TO 3

choice% = RND AND 1

IF choice% THEN sequence$ += "H" ELSE sequence$ += "T"

NEXT

= sequence$

:

DEF FN_optimal(sequence$)

IF MID$(sequence$, 2, 1) = "H" THEN

= "T" + LEFT$(sequence$, 2)

ELSE

= "H" + LEFT$(sequence$, 2)

ENDIF</lang>

{{out}}

<pre>*** Penney's Game ***

Heads you pick first, tails I pick first.

And it is... heads!

Enter a sequence of three choices, each of them either H or T:

> HTT

I choose HHT.

Starting the game...

H H H H H T

I won!

Another game? (Y/N) Y

Heads you pick first, tails I pick first.

And it is... tails!

I choose HTH.

Enter a sequence of three choices, each of them either H or T:

> HHT

Starting the game...

T T H H H H T

Congratulations! You won.

Another game? (Y/N) N

Thank you for playing!</pre>