# Go Fish/Unicon

This is a two player version of Go Fish with a 9 card deal out where the human player always goes first. It is assumed that everyone will know what cards are booked out and what cards are fished. The computer acts as arbitrator so there is no way to lie, cheat, or steal.

Also, this program uses a simplified deck (no suits but four of each card) similar to some children's specialty decks.

The computer strategy relies on the following facts and public knowledge which are kept for each player in the player's public field. Public is a table by rank. A value of -1 indicates unknown state, any other value is the known number of cards.

• a. Public counts can be adjusted when a player makes a book.
• b. If the opponent asks for a card an unknown can be changed to a 1 as they have at least one card of this rank.
• c. When one or more cards are surrendered during fishing , the public counts of both players can be adjusted accordingly.
• d. A card drawn requires that counts of 0 be set to unknown unless the cards were booked out.

Strategy:

• (i) Request any known cases of 3 of a kind first.
• (ii) Request from other known cards second. The request should be in proportion to what you do not hold in your hand. That is if you have 1 J, you should have 3 chances of requesting it.
• (iii) Guess. This should also be in inverse proportion to what you hold in your hand.
```link printf,strings

global GF                                                   # global game state
record GFgame(ranks,suits,dealt,booked,deck,HP,AI)          # game record

procedure main()                                #: 2 player go-fish human vs. AI
GF := GFgame("23456789TJQKA", 4, 9, "")            # game parameters
GF.deck := scramble(repl(GF.ranks,GF.suits))       # shuffled deck
GF.HP   := GFplayer("Human"   ,0,HPaskAI,"",table(-1))    # Human player
GF.AI   := GFplayer("Computer",0,AIaskHP,"",table(-1))    # Computer player
every 1 to GF.dealt do DrawCard(GF.HP) & DrawCard(GF.AI)  # Deal cards
printf("Go fish.\nYou vs. the computer - your turn first:\n")
while PlayerTurn(GF.HP,GF.AI) & PlayerTurn(GF.AI,GF.HP)   # play until done
printf("Final score:  Computer=%d, Human=%d - %s wins.\n",
GF.AI.score,GF.HP.score,
if GF.HP.score > GF.AI.score then GF.HP.name else GF.AI.name)
end

procedure PlayerTurn(player,opponent)           #: Player's turn
if *GF.booked < *GF.ranks then {                   # play until done
ifbook(player)                                  # made a book ?
while PlayerFishes(player,opponent)             # fish while successful
return                                          # signal continue
}
end

procedure PlayerFishes(player,opponent)         #: player fishes for a card
if 0 < strcnt(r := player.ask(),player.hand) then {# ask - any in hand?
player.public[r] <:= 1                          # either way - at least one
opponent.public[r] := 0                         # either way -none
if k := 0 < strcnt(r,opponent.hand) then {      # opponent has k > 0 r's?
printf("Yes, there was %d %s('s)\n",k,r)
opponent.hand := deletec(opponent.hand,r)    # move from opponent
player.hand ||:= repl(r,k)                   # to player
player.public[r] +:= k                       # k more in hand
if *opponent.hand = 0 then DrawCard(opponent)# hand empty ?
ifbook(player)                               # made a book ?
if *player.hand > 0 then return              # signal success if cards left
}
else {
printf("No, %s has no %s's - %s draws a card\n",opponent.name,r,player.name)
DrawCard(player)                             # draw from deck
ifbook(player)                               # made a book ?
}
}
else
printf("%s is out of cards\n",player.name)   #
end

procedure ifbook(player)                        #: determine if a book made
every r := !GF.ranks do
if strcnt(r,player.hand) = GF.suits then {      # yes
printf("%s made a book of %s's\n",player.name,r)
player.hand := deletec(player.hand,r)        # remove trick from hand
player.public[r] := 0                        # no longer in hand
player.score +:= 1                           # score 1
GF.booked ||:= r                             # book trick
if *player.hand = 0 then DrawCard(player)    # draw if hand empty
return
}
end

procedure DrawCard(player)                      #: draw a card from the deck
if player.hand ||:= r := GF.deck[1] then {         # card if any to player
GF.deck[1] := ""                                # and out of deck
every r := !GF.ranks do                         # 0's back to uncertainty
if player.public[r] = 0 & not find(r,GF.booked) then
player.public[r] := -1
return
}
end

procedure GFstrategy(player,opponent)           #: Request Strategy
every (knowns := "") ||:= key(opponent.public)
knowns := string(knowns**player.hand)              # we know we can win
every r := !knowns do
if opponent.public[r] = GF.suits -1 then        # we can make a trick
return r
else
ask ||:= repl(r,0 < opponent.public[r])      # weighted knowns
return ?ask                                     # random choice by weight
every (guess := "") ||:=
repl(c := !cset(player.hand),GF.suits-strcnt(c,player.hand))
every ( z := '') ++:= (0 = opponent.public[r := !GF.ranks],r)
guess := deletec(guess,z)
if *guess = 0 then guess := (z ** player.hand)[1]  # make fruitless guess
return ?guess
end

if r := \GFstrategy(GF.AI,GF.HP) then {            # use strategy
printf("Computer: Do you have any %s's?\n",r)
return r
}
end

repeat {
if *r = 1 & 0 < strcnt(r,GF.HP.hand) then break
else
printf("Try again, you must have at least one %i in your hand\n",r)
else
printf("Invalid rank %i, must be one of %i\n",r,GF.ranks)
}
printf("You: Does the computer have any %s's?\n",r)
return r
end
```

Sample Game:

```Go fish.
You vs. the computer - your turn first:
You: Does the computer have any K's?
Yes, there was 2 K('s)
You: Does the computer have any J's?
Yes, there was 1 J('s)
You: Does the computer have any A's?
No, Computer has no A's - Human draws a card
Computer: Do you have any 3's?
Yes, there was 1 3('s)
Computer: Do you have any 5's?
No, Human has no 5's - Computer draws a card
You: Does the computer have any 4's?
Yes, there was 2 4('s)
You: Does the computer have any 6's?
Yes, there was 2 6('s)
You: Does the computer have any 8's?
No, Computer has no 8's - Human draws a card
Computer: Do you have any 3's?
No, Human has no 3's - Computer draws a card
You: Does the computer have any Q's?
No, Computer has no Q's - Human draws a card
Computer: Do you have any 3's?
No, Human has no 3's - Computer draws a card
You: Does the computer have any K's?
No, Computer has no K's - Human draws a card
Computer: Do you have any 3's?
No, Human has no 3's - Computer draws a card
You: Does the computer have any T's?
Yes, there was 1 T('s)
You: Does the computer have any J's?
No, Computer has no J's - Human draws a card
Computer: Do you have any 2's?
No, Human has no 2's - Computer draws a card
You: Does the computer have any A's?
No, Computer has no A's - Human draws a card
Computer: Do you have any J's?
Yes, there was 2 J('s)
Computer: Do you have any 7's?
No, Human has no 7's - Computer draws a card
You: Does the computer have any 4's?
Yes, there was 1 4('s)
Human made a book of 4's
You: Does the computer have any 6's?
No, Computer has no 6's - Human draws a card
Computer: Do you have any 5's?
No, Human has no 5's - Computer draws a card
You: Does the computer have any 8's?
No, Computer has no 8's - Human draws a card
Computer: Do you have any 2's?
Yes, there was 1 2('s)
Computer: Do you have any 3's?
Yes, there was 1 3('s)
Computer: Do you have any 7's?
No, Human has no 7's - Computer draws a card
You: Does the computer have any T's?
No, Computer has no T's - Human draws a card
Human made a book of 6's
Computer: Do you have any 7's?
No, Human has no 7's - Computer draws a card
You: Does the computer have any Q's?
No, Computer has no Q's - Human draws a card
Computer: Do you have any 8's?
Yes, there was 3 8('s)
Computer made a book of 8's
Computer: Do you have any J's?
Yes, there was 1 J('s)
Computer made a book of J's
Computer: Do you have any 9's?
No, Human has no 9's - Computer draws a card
You: Does the computer have any A's?
No, Computer has no A's - Human draws a card
Computer: Do you have any 7's?
Yes, there was 1 7('s)
Computer: Do you have any 9's?
No, Human has no 9's - Computer draws a card
You: Does the computer have any K's?
No, Computer has no K's - Human draws a card
Computer: Do you have any T's?
Yes, there was 2 T('s)
Computer: Do you have any 9's?
Yes, there was 1 9('s)
Computer: Do you have any 2's?
No, Human has no 2's - Computer draws a card
You: Does the computer have any 5's?
Yes, there was 2 5('s)
You: Does the computer have any Q's?
Yes, there was 1 Q('s)
You: Does the computer have any K's?
No, Computer has no K's - Human draws a card
Computer: Do you have any 2's?
No, Human has no 2's - Computer draws a card
You: Does the computer have any T's?
Yes, there was 3 T('s)
Human made a book of T's
You: Does the computer have any 5's?
No, Computer has no 5's - Human draws a card
Computer: Do you have any Q's?
Yes, there was 3 Q('s)
Computer made a book of Q's
Computer: Do you have any 7's?
No, Human has no 7's - Computer draws a card
You: Does the computer have any 2's?
Yes, there was 3 2('s)
Human made a book of 2's
You: Does the computer have any 5's?
No, Computer has no 5's - Human draws a card
Computer: Do you have any A's?
Yes, there was 3 A('s)
Computer made a book of A's
Computer: Do you have any 7's?
No, Human has no 7's - Computer draws a card
You: Does the computer have any 3's?
Yes, there was 3 3('s)
Human made a book of 3's
You: Does the computer have any K's?
No, Computer has no K's - Human draws a card
Human made a book of 5's
Computer: Do you have any 7's?
No, Human has no 7's - Computer draws a card
Computer made a book of 9's