Battleship (== Sea battle, naval battle)

[tsh73]

It started from this thread
justbasiccom.proboards.com/thread/1121/naval-battle-2-players
I wanted to roll my own arrays (in one big one) to be able to reuse code for different arrays
I had something working but end with conclusion what it does not worth it ;)

but as a second try, I made something like Battleship engine
(still on a single big array)
Now it fiercely plays against itself ;)
in a mainwin.

I probably make it into playable mainwin game
(now it miss big chunk - code for user placing ships)

Idea was that character arrays could be easily transferred to GUI (just draw certain sprite for certain letter ),
but placing ships calls for drag'n'drop so this part should be completely new.

Now it asks for field size (10x10 or 8x8) and ships set
Ships set for 8x8 was googled picture. It plays faster (but it looks like player 1 wins most of the time).
Ships are horisontal or vertical, no turns
Ships could not touch each other
Player who hit a ship gets next shot
(with this, game plays faster. But it is possible one lucky player to quickly finish other one!)

few screeenshots (it is actually text from a mainwin!)
----====****  BATTLESHIP  ****====----

Select field size (0-10x10, 1=8x8):
 Field set to 10x10
Select ship set
   Milton/Hasbro (5 4 3 3 2)
   USSR (4 3 3 2 2 2 1 1 1 1)
Select ship set (0-Milton, 1=USSR):
 Ship set is Milton/Hasbro



Generating ships for player 1
aaaaa
bbbb
ccc
ddd
ee

   A B C D E F G H I J
  ---------------------
1| . . d d d . . . c .
2| . . . . . . . . c .
3| . . . . . . . . c .
4| . . b b b b . . . .
5| . . . . . . . . . e
6| . . . . . . . . . e
7| . . . . . . . . . .
8| . . . . . . . . . .
9| . . . a a a a a . .
10| . . . . . . . . . .
  ---------------------
   A B C D E F G H I J



press ENTER to start auto-game

While autoplaying, program shows radar for player1(left) and player2 (right)
Current shot shows in a caps lock. oO miss, xX hit.
(+) is "shadow" cells where ship could not be placed - it's mark for the AI not to shoot there.
Player scoring a hit gets next move.
B1
miss
. O o . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .
                        J6
                        hit
                         . . . . . . . . . .
                         . . . . . . . . . .
                         . . o . . . . . . .
                         . . . . . . . . . .
                         . . . . . . . . + .
                         . . . . . . . . . X
                         . . . . . . . . + .
                         . . . . . . . . . .
                         . . . . . . . . . .
                         . . . . . . . . . .
                        I6
                        miss
                         . . . . . . . . . .
                         . . . . . . . . . .
                         . . o . . . . . . .
                         . . . . . . . . . .
                         . . . . . . . . + .
                         . . . . . . . . O x
                         . . . . . . . . + .
                         . . . . . . . . . .
                         . . . . . . . . . .
                         . . . . . . . . . .

When ship is killed, program says "kill" and finish encircling ship with (+)
E6
kill
. o o . . . . . . .
. . . + + + . . . .
. . . + x + . . . .
. . . + x + . . . .
. . . + x + . . . .
. . . + X + . . . .
. . o + + + . . . .
. . . . . . . . . .
. . . . . . . . . .
. . . . . . . . . .


Eventually, one player runs out of ships
so game register "win"
J1
win
. o o o . o + x x X
o o o + + + o + + o
+ + + + x + o . o .
+ x + + x + . . + o
+ x + + x + . . + x
+ o + + x + o . + x
. o o + + + . . + x
. o . . . . . . + x
. . o + + o + + + x
. . . + x x x + + o

Player 1 wins!
 turns:41


In the end it shows ships of both players. Obviously, one who got nothing but "x" left loses
   A B C D E F G H I J
  ---------------------
1| . . d d d . . . X .
2| . . . . . . . . X .
3| . . . . . . . . X .
4| . . X X X X . . . .
5| . . . . . . . . . X
6| . . . . . . . . . X
7| . . . . . . . . . .
8| . . . . . . . . . .
9| . . . X X X X X . .
10| . . . . . . . . . .
  ---------------------
   A B C D E F G H I J

                            A B C D E F G H I J
                           ---------------------
                         1| . . . . . . . X X X
                         2| . . . . . . . . . .
                         3| . . . . X . . . . .
                         4| . X . . X . . . . .
                         5| . X . . X . . . . X
                         6| . . . . X . . . . X
                         7| . . . . . . . . . X
                         8| . . . . . . . . . X
                         9| . . . . . . . . . X
                        10| . . . . X X X . . .
                           ---------------------
                            A B C D E F G H I J

press ENTER to quit


AI remembers "last hit", and continues to hunt that ship, even after miss.
(actually until ship is killed, it remembers all its hit points. So you hardly can escape)

Example setup for 8x8 field
----====****  BATTLESHIP  ****====----

Select field size (0-10x10, 1=8x8):1
 Field set to 8x8
 Ship set (5 4 3 2 2 1 1)

Generating ships for player 1
aaaaa
bbbb
ccc
dd
ee
f
g

   A B C D E F G H
  -----------------
1| e e . . f . . .
2| . . . . . . . .
3| . . . a . b . .
4| . . . a . b . .
5| . g . a . b . c
6| . . . a . b . c
7| . . . a . . . c
8| d d . . . . . .
  -----------------
   A B C D E F G H


Example setup for 10x10 field, USSR ship set
----====****  BATTLESHIP  ****====----

Select field size (0-10x10, 1=8x8):
 Field set to 10x10
Select ship set
   Milton/Hasbro (5 4 3 3 2)
   USSR (4 3 3 2 2 2 1 1 1 1)
Select ship set (0-Milton, 1=USSR):1
 Ship set is USSR

Generating ships for player 1
aaaa
bbb
ccc
dd
ee
ff
g
h
i
j

   A B C D E F G H I J
  ---------------------
1| . . . . . . g . . .
2| . a a a a . . . . .
3| . . . . . . . . . .
4| j . c c c . e . . .
5| . . . . . . e . . h
6| . . . . . . . . . .
7| . . . f f . . . d d
8| . . . . . . . . . .
9| i . . . . b b b . .
10| . . . . . . . . . .
  ---------------------
   A B C D E F G H I J


[tsh73]

Current code (v.14)
'sea battle 01
'    array management, now console
'v.14

global N, player1, player2, shadow, radar
global shipList$

print "----====****  BATTLESHIP  ****====----"
print
input "Select field size (0-10x10, 1=8x8):";n1
if n1=0 then N=10 else N=8
print "  Field set to ";N;"x";N
if N=10 then
print "Select ship set"
print "    Milton/Hasbro (5 4 3 3 2)"
print "    USSR (4 3 3 2 2 2 1 1 1 1)"
input "Select ship set (0-Milton, 1=USSR):";n2
if n2=0 then
print "  Ship set is Milton/Hasbro"
shipList$="a5  b4  c3 d3 e2"    'classic
else
print "  Ship set is USSR"
shipList$="a4  b3 c3  d2 e2 f2  g1 h1 i1 j1"    'Russian traditional
end if
else
print "  Ship set (5 4 3 2 2 1 1)"
shipList$="a5  b4  c3  d2 e2  f1 g1"    '8x8 ships
end if

' input "press ENTER to quit"; d$
' end

'N=10
'N=8
player1=0
player2=100    'enough space to store all player1 data
shadow=20
radar=40

dim a$(2*player2,N+1)    'row, col. row+ displacement gives player2 etc
dim prevHit$(player2) 'actually need 2 cells, but I'll use 0 and 100

'letter, number of cells
'shipList$="a4  b3 c3  d2 e2 f2  g1 h1 i1 j1"    'Russian traditional
'shipList$="a5  b4  c3 d3 e2"    'classic
'shipList$="a5  b4  c3  d2 e2  f1 g1"    '8x8 ships
'shipList$="a1  b1 c1  d1 e1 f1  g1 h1 i1 j1"    'test for kill

print
call generate2 player1
call showArr1 player1

print
call generate2 player2
call showArr1 player2

print
input "press ENTER to start auto-game"; d$

player=player1
prevHit$=""
for i = 1 to 200
do
res$= shoot5$(player)
if player>=player2 then print space$(5+N*2);
print res$
call showArr player+radar
call toLower player+radar
if res$="win" then
print
print "Player "; (player=player2)+1;" wins!"
print "  turns:";i
call showArr1 player1
print
call showArr1 player2
print
input "press ENTER to quit"; d$
end
end if
loop until res$="miss" 'if not miss, extra move!
player=player2-player
next

input "press ENTER to quit"; d$
end

sub showArr offset
for r = 1 to N
if offset>=player2 then print space$(5+N*2);
   for c = 1 to N
       c$="."
       if a$(offset+r, c)<>"" and a$(offset+r, c)<>" " then c$=a$(offset+r, c)
       print " ";c$;
   next
   print
next
end sub

sub showArr1 offset
ln$=left$("-----------------------------------------------------",N*2+1)
ltr$=left$(" A B C D E F G H I J K L M N O P Q R S T U V W X Y Z ",N*2)
if offset>=player2 then off$ = space$(5+N*2)
print off$;"   ";ltr$
print off$;"   ";ln$
for r = 1 to N
print off$;using("##",r);"|";
for c = 1 to N
c$="."
if a$(offset+r, c)<>"" and a$(offset+r, c)<>" " then c$=a$(offset+r, c)
print " ";c$;
next
print
next
print off$;"   ";ln$
print off$;"   ";ltr$
end sub

sub clearArr offset
for r = 1 to N
for c = 1 to N
a$(offset+r, c)=""
next
next
end sub

sub generate2 player 'with check
'clear player
call clearArr player
call clearArr player+shadow

if player>=player2 then off$ = space$(5+N*2)
print "Generating ships for player ";(player=player2)+1
i=0
while 1
i=i+1
w$=word$(shipList$,i)
if w$="" then exit while
c$=left$(w$,1)
n=val(mid$(w$,2))
print off$;:for j = 1 to n:print c$;:next:print
k=0
while 1
k=k+1
if k>500 then 'if we cannot do it that long, just start over
print "*start over*"
call generate2 player
exit sub
end if
isVert=rnd(1)>.5
isHor=1-isVert
r=int(rnd(0)*(N-isVert*(n-1))+1)
c=int(rnd(0)*(N-isHor*(n-1))+1)  
'have to check first
forbidden=0
for j = 0 to n-1
forbidden=forbidden+( a$(player+shadow+r+j*isVert, c+j*isHor)="#" )
next
if not (forbidden) then
for j = 0 to n-1
a$(player+r+j*isVert, c+j*isHor)=c$
next
call mkShadow player
exit while
end if
wend
'print k;" ";
wend
print
end sub

sub mkShadow player
for r = 1 to N
for c = 1 to N
if a$(player+r, c)<>"" and a$(player+r, c)<>" " then
for i = -1 to 1
for j = -1 to 1
a$(player+shadow+r+i, c+j)="#"
next
next
end if
next
next
end sub

sub mkRadarShadow2.1 player
for r = 1 to N
for c = 1 to N
if a$(player+radar+r, c)="#" then
for i = -1 to 1
for j = -1 to 1
if a$(player+radar+r+i, c+j)="" or a$(player+radar+r+i, c+j)=" " then
a$(player+radar+r+i, c+j)="+"
end if
next
next
end if
next
next
end sub

sub mkRadarShadow2 player, r,c
'paint-like from shoot$
'notice "TBD! "+chr$(13)+"sub mkRadarShadow2 player, shoot$"
'input "press Ener to quit"; d$
'end
call paintKilled player+radar,r,c 'mark fresh kill
call mkRadarShadow2.1 player
'hide fresh kill mark
for r = 1 to N
for c = 1 to N
if a$(player+radar+r, c)="#" then a$(player+radar+r, c)="x"
next
next

end sub

sub paintKilled offset,r,c
a$(offset+r,c)="#"
if a$(offset+r-1,c)="x" then call paintKilled offset,r-1,c
if a$(offset+r+1,c)="x" then call paintKilled offset,r+1,c
if a$(offset+r,c-1)="x" then call paintKilled offset,r,c-1
if a$(offset+r,c+1)="x" then call paintKilled offset,r,c+1
end sub

function shoot5$(player)
if  prevHit$(player)<>"" then
list$=""
while 1
k=k+1
w$=word$(prevHit$(player),k)
if w$="" then exit while
'
r0=val(word$(w$,1,","))
c0=val(word$(w$,2,","))
list$=addNeighbourFreeList$(player+radar,r0,c0, list$)
wend
end if
if  list$="" then
list$=mkFreeList$(player+radar)
end if
if  list$="" then 'or cource should not happen, but...
print "ERROR! player ";((player=player2)+1);" have no unchecked cells on radar!"
input "press ENTER to quit";d$
end
end if
shoot$=randomSelect$(list$)
r=val(word$(shoot$,1,","))
c=val(word$(shoot$,2,","))
if player>=player2 then print space$(5+N*2);
print chr$(asc("A")-1+c);r
enemy=player2-player
'if rnd(1)>.8 then
if a$(enemy+r, c)<>" " and a$(enemy+r, c)<>"" then
marker$=a$(enemy+r, c)
a$(player+radar+r, c)="X" 'current shot - hit
a$(enemy+r, c)="X" 'current shot - hit
if countMarker(enemy, marker$) then
res$="hit"
prevHit$(player)=prevHit$(player);" ";shoot$ 'a list
call mkRadarDiagShadow player, r,c
else
res$="kill"
call mkRadarShadow2 player, r,c 'TBD
''call mkRadarDiagShadow player, r,c 'instead
a$(player+radar+r, c)="X" 'restore last shot
prevHit$(player)="" 'release only on kill!
if countLeft(enemy)=0 then res$="win"
end if
else
a$(player+radar+r, c)="O" 'current shot - miss
res$="miss" 'but prevHit$ stays
end if
shoot5$=res$
end function

sub toLower offset
for r = 1 to N
for c = 1 to N
a$(offset+r, c)=lower$(a$(offset+r, c))
next
next
end sub

function countMarker(enemy, marker$)
countMarker=0 'should count
for r = 1 to N
for c = 1 to N
if a$(enemy+r, c)=marker$ then countMarker=countMarker+1
next
next
end function

function countLeft(enemy)
countLeft=0 'should count
for r = 1 to N
for c = 1 to N
if a$(enemy+r, c)<>"" and instr(" xXoO", a$(enemy+r, c))=0 then countLeft=countLeft+1
next
next
end function

function mkFreeList$(offset)
for r = 1 to N
for c = 1 to N
if a$(offset+r, c)="" or a$(offset+r, c)=" " then list$=list$;" ";r;",";c
next
next
mkFreeList$=list$
end function

sub mkRadarDiagShadow player,r0,c0
offset=player+radar
r=r0-1:c=c0-1
if r>0 and r<=N and c>0 and c<=N then
if a$(offset+r, c)="" or a$(offset+r, c)=" " then a$(offset+r, c)="+"
end if
r=r0-1:c=c0+1
if r>0 and r<=N and c>0 and c<=N then
if a$(offset+r, c)="" or a$(offset+r, c)=" " then a$(offset+r, c)="+"
end if
r=r0+1:c=c0-1
if r>0 and r<=N and c>0 and c<=N then
if a$(offset+r, c)="" or a$(offset+r, c)=" " then a$(offset+r, c)="+"
end if
r=r0+1:c=c0+1
if r>0 and r<=N and c>0 and c<=N then
if a$(offset+r, c)="" or a$(offset+r, c)=" " then a$(offset+r, c)="+"
end if
end sub

function addNeighbourFreeList$(offset,r0,c0, list$)
r=r0:c=c0-1
if r>0 and r<=N and c>0 and c<=N then
if a$(offset+r, c)="" or a$(offset+r, c)=" " then list$=addUniq$(list$, r;",";c)
end if
r=r0:c=c0+1
if r>0 and r<=N and c>0 and c<=N then
if a$(offset+r, c)="" or a$(offset+r, c)=" " then list$=addUniq$(list$, r;",";c)
end if
r=r0-1:c=c0
if r>0 and r<=N and c>0 and c<=N then
if a$(offset+r, c)="" or a$(offset+r, c)=" " then list$=addUniq$(list$, r;",";c)
end if
r=r0+1:c=c0
if r>0 and r<=N and c>0 and c<=N then
if a$(offset+r, c)="" or a$(offset+r, c)=" " then list$=addUniq$(list$, r;",";c)
end if
addNeighbourFreeList$=list$
end function

function addUniq$(list$, item$)
if instr(" ";list$;" ", " ";item$;" ")=0 then
addUniq$=list$;" ";item$
else
addUniq$=list$
end if
end function

function countItems(list$)
do
i=i+1
w$=word$(list$,i)
loop until w$=""
countItems=i-1
end function

function randomSelect$(list$)
r=randInt1(countItems(list$))
randomSelect$=word$(list$,r)
end function

function randInt(n) '0..n-1
randInt=int(rnd(1)*n)
end function

function randInt1(n) '1..n
randInt1=int(rnd(1)*n)+1
end function


[tsh73]

Ok, game is playable now - all but ship placing.
Looks working - I even winned it over once! ;)
It flips coin to determine is human Player1 (first) or Player2
Computer move shows result on player map with ships
Player move shows only player radar
(I could probably remove AI '+' marks from it. But you have it in mind then playing anyway, aren't you?)
(autoplay is retained as an option. Autoplay shows radars for both computer players)

---

EDIT: just made my kid play it. Human wins! ;)
'sea battle 01
'    array management, now console
'v.15

global N, player1, player2, human, shadow, radar
global shipList$, autoplay

'N=10
'N=8
player1=0
player2=100     'offset - enough space to store all player1 data
shadow=20 'point was storing 0..N+1 lines for actual ship map, shadow used to place ships, radar
radar=40 '0 and N+1 is unused but prevenst out of array errors

print "----====****  BATTLESHIP  ****====----"
print
input "Select field size (0-10x10, 1=8x8):";n1
if n1=0 then N=10 else N=8
print "  Field set to ";N;"x";N
if N=10 then
print "Select ship set"
print "    Milton/Hasbro (5 4 3 3 2)"
print "    USSR (4 3 3 2 2 2 1 1 1 1)"
input "Select ship set (0-Milton, 1=USSR):";n2
if n2=0 then
print "  Ship set is Milton/Hasbro"
shipList$="a5  b4  c3 d3 e2"    'classic
else
print "  Ship set is USSR"
shipList$="a4  b3 c3  d2 e2 f2  g1 h1 i1 j1"    'Russian traditional
end if
else
print "  Ship set (5 4 3 2 2 1 1)"
shipList$="a5  b4  c3  d2 e2  f1 g1"    '8x8 ships
end if

print
input "Press Enter to flip the coin, 1 for autoplay";n3
if n3=0 then
Print
Print "Flipping the coin..."
if rnd(0)<.5 then
human=player1
Print "  You are Player1."' Your turn!"
else
human=player2
Print "  You are Player2."' Computer turn!"
end if
else
autoplay=1
print "  Preparing autoplay..."
end if
'input "press ENTER to quit"; d$' end

dim a$(2*player2,N+1)    'row, col. row+ displacement gives player2 etc
dim prevHit$(player2) 'actually need 2 cells, but I'll use 0 and 100

'letter, number of cells
'shipList$="a4  b3 c3  d2 e2 f2  g1 h1 i1 j1"    'Russian traditional
'shipList$="a5  b4  c3 d3 e2"    'classic
'shipList$="a5  b4  c3  d2 e2  f1 g1"    '8x8 ships
'shipList$="a1  b1 c1  d1 e1 f1  g1 h1 i1 j1"    'test for kill

if autoplay then
print
call generate2 player1
call showArr1 player1

print
call generate2 player2
call showArr1 player2

print
input "press ENTER to start auto-game"; d$
else
if human=player2 then
call generate2 player1
print
print "Player2, please place your ships"
print "  wait, not ready yet. Let me place it for you..."
call generate2 player2
call showArr1 player2
else
print "Player1, please place your ships"
print "  wait, not ready yet. Let me place it for you..."
call generate2 player1
call showArr1 player1
print
call generate2 player2
end if
print
input "press ENTER to start game"; d$
if human=player1 then
Print "  You are Player1. Your turn!"
else
Print "  You are Player2. Computer turn!"
end if
end if

player=player1
prevHit$=""
for i = 1 to 200
do
res$= shoot5$(player)
if player>=player2 then print space$(5+N*2);
print res$
if not(autoplay) and (player<>human) then
call showArr1 human
call toLower human
else
call showArr1 player+radar
end if
call toLower player+radar
if res$="win" then
print
print "Player "; (player=player2)+1;" wins!"
print "  turns:";i
call showArr1 player1
print
call showArr1 player2
print
input "press ENTER to quit"; d$
end
end if
loop until res$="miss" 'if not miss, extra move!
player=player2-player
next

input "press ENTER to quit"; d$
end

sub showArr offset
for r = 1 to N
if offset>=player2 then print space$(5+N*2);
   for c = 1 to N
       c$="."
       if a$(offset+r, c)<>"" and a$(offset+r, c)<>" " then c$=a$(offset+r, c)
       print " ";c$;
   next
   print
next
end sub

sub showArr1 offset
ln$=left$("-----------------------------------------------------",N*2+1)
ltr$=left$(" A B C D E F G H I J K L M N O P Q R S T U V W X Y Z ",N*2)
if not(autoplay) and (offset=human) then 'offset reversed
if offset<player2 then off$ = space$(5+N*2)
else
if offset>=player2 then off$ = space$(5+N*2)
end if
print off$;"   ";ltr$
print off$;"   ";ln$
for r = 1 to N
print off$;using("##",r);"|";
for c = 1 to N
c$="."
if a$(offset+r, c)<>"" and a$(offset+r, c)<>" " then c$=a$(offset+r, c)
print " ";c$;
next
print
next
print off$;"   ";ln$
print off$;"   ";ltr$
end sub

sub clearArr offset
for r = 1 to N
for c = 1 to N
a$(offset+r, c)=""
next
next
end sub

sub generate2 player 'with check
'clear player
call clearArr player
call clearArr player+shadow

if player>=player2 then off$ = space$(5+N*2)
print "Generating ships for player ";(player=player2)+1
i=0
while 1
i=i+1
w$=word$(shipList$,i)
if w$="" then exit while
c$=left$(w$,1)
n=val(mid$(w$,2))
print off$;:for j = 1 to n:print c$;:next:print
k=0
while 1
k=k+1
if k>500 then 'if we cannot do it that long, just start over
print "*start over*"
call generate2 player
exit sub
end if
isVert=rnd(1)>.5
isHor=1-isVert
r=int(rnd(0)*(N-isVert*(n-1))+1)
c=int(rnd(0)*(N-isHor*(n-1))+1)  
'have to check first
forbidden=0
for j = 0 to n-1
forbidden=forbidden+( a$(player+shadow+r+j*isVert, c+j*isHor)="#" )
next
if not (forbidden) then
for j = 0 to n-1
a$(player+r+j*isVert, c+j*isHor)=c$
next
call mkShadow player
exit while
end if
wend
'print k;" ";
wend
print
end sub

sub mkShadow player
for r = 1 to N
for c = 1 to N
if a$(player+r, c)<>"" and a$(player+r, c)<>" " then
for i = -1 to 1
for j = -1 to 1
a$(player+shadow+r+i, c+j)="#"
next
next
end if
next
next
end sub

sub mkRadarShadow2.1 player
for r = 1 to N
for c = 1 to N
if a$(player+radar+r, c)="#" then
for i = -1 to 1
for j = -1 to 1
if a$(player+radar+r+i, c+j)="" or a$(player+radar+r+i, c+j)=" " then
a$(player+radar+r+i, c+j)="+"
end if
next
next
end if
next
next
end sub

sub mkRadarShadow2 player, r,c
'paint-like from shoot$
'notice "TBD! "+chr$(13)+"sub mkRadarShadow2 player, shoot$"
'input "press Ener to quit"; d$
'end
call paintKilled player+radar,r,c 'mark fresh kill
call mkRadarShadow2.1 player
'hide fresh kill mark
for r = 1 to N
for c = 1 to N
if a$(player+radar+r, c)="#" then a$(player+radar+r, c)="x"
next
next

end sub

sub paintKilled offset,r,c
a$(offset+r,c)="#"
if a$(offset+r-1,c)="x" then call paintKilled offset,r-1,c
if a$(offset+r+1,c)="x" then call paintKilled offset,r+1,c
if a$(offset+r,c-1)="x" then call paintKilled offset,r,c-1
if a$(offset+r,c+1)="x" then call paintKilled offset,r,c+1
end sub

function shoot5$(player)
'AI part
enemy=player2-player
if autoplay or (player<>human) then
if  prevHit$(player)<>"" then
list$=""
while 1
k=k+1
w$=word$(prevHit$(player),k)
if w$="" then exit while
'
r0=val(word$(w$,1,","))
c0=val(word$(w$,2,","))
list$=addNeighbourFreeList$(player+radar,r0,c0, list$)
wend
end if
if  list$="" then
list$=mkFreeList$(player+radar)
end if
if  list$="" then 'or cource should not happen, but...
print "ERROR! player ";((player=player2)+1);" have no unchecked cells on radar!"
input "press ENTER to quit";d$
end
end if
shoot$=randomSelect$(list$)
r=val(word$(shoot$,1,","))
c=val(word$(shoot$,2,","))
else
'ask player
while 1
input "Enter coords to fire, like a1: ";shoot0$
shoot0$=trim$(lower$(shoot0$))
r=val(mid$(shoot0$,2))
c=instr("abcdefghij", left$(shoot0$,1))
if (c>0) and (c <11) and (r>0) and (r <11) then exit while
Print "Got row=";r;" col=";c;". Not valid!"
wend
shoot$=r;",";c
if a$(enemy+r, c)="x" or a$(enemy+r, c)="o" then
print "  Already fired at - your wasted your turn!"
res$="miss"
shoot5$=res$
exit function
end if
end if
if player>=player2 then print space$(5+N*2);
print "Player";((player=player2)+1);" ";
print chr$(asc("A")-1+c);r
'if rnd(1)>.8 then
if a$(enemy+r, c)<>" " and a$(enemy+r, c)<>"" then
marker$=a$(enemy+r, c)
a$(player+radar+r, c)="X" 'current shot - hit
a$(enemy+r, c)="X" 'current shot - hit
if countMarker(enemy, marker$) then
res$="hit"
prevHit$(player)=prevHit$(player);" ";shoot$ 'a list
call mkRadarDiagShadow player, r,c
else
res$="kill"
call mkRadarShadow2 player, r,c 'TBD
''call mkRadarDiagShadow player, r,c 'instead
a$(player+radar+r, c)="X" 'restore last shot
prevHit$(player)="" 'release only on kill!
if countLeft(enemy)=0 then res$="win"
end if
else
a$(player+radar+r, c)="O" 'current shot - miss
a$(enemy+r, c)="O"
res$="miss" 'but prevHit$ stays
end if
shoot5$=res$
end function

sub toLower offset
for r = 1 to N
for c = 1 to N
a$(offset+r, c)=lower$(a$(offset+r, c))
next
next
end sub

function countMarker(enemy, marker$)
countMarker=0 'should count
for r = 1 to N
for c = 1 to N
if a$(enemy+r, c)=marker$ then countMarker=countMarker+1
next
next
end function

function countLeft(enemy)
countLeft=0 'should count
for r = 1 to N
for c = 1 to N
if a$(enemy+r, c)<>"" and instr(" xXoO", a$(enemy+r, c))=0 then countLeft=countLeft+1
next
next
end function

function mkFreeList$(offset)
for r = 1 to N
for c = 1 to N
if a$(offset+r, c)="" or a$(offset+r, c)=" " then list$=list$;" ";r;",";c
next
next
mkFreeList$=list$
end function

sub mkRadarDiagShadow player,r0,c0
offset=player+radar
r=r0-1:c=c0-1
if r>0 and r<=N and c>0 and c<=N then
if a$(offset+r, c)="" or a$(offset+r, c)=" " then a$(offset+r, c)="+"
end if
r=r0-1:c=c0+1
if r>0 and r<=N and c>0 and c<=N then
if a$(offset+r, c)="" or a$(offset+r, c)=" " then a$(offset+r, c)="+"
end if
r=r0+1:c=c0-1
if r>0 and r<=N and c>0 and c<=N then
if a$(offset+r, c)="" or a$(offset+r, c)=" " then a$(offset+r, c)="+"
end if
r=r0+1:c=c0+1
if r>0 and r<=N and c>0 and c<=N then
if a$(offset+r, c)="" or a$(offset+r, c)=" " then a$(offset+r, c)="+"
end if
end sub

function addNeighbourFreeList$(offset,r0,c0, list$)
r=r0:c=c0-1
if r>0 and r<=N and c>0 and c<=N then
if a$(offset+r, c)="" or a$(offset+r, c)=" " then list$=addUniq$(list$, r;",";c)
end if
r=r0:c=c0+1
if r>0 and r<=N and c>0 and c<=N then
if a$(offset+r, c)="" or a$(offset+r, c)=" " then list$=addUniq$(list$, r;",";c)
end if
r=r0-1:c=c0
if r>0 and r<=N and c>0 and c<=N then
if a$(offset+r, c)="" or a$(offset+r, c)=" " then list$=addUniq$(list$, r;",";c)
end if
r=r0+1:c=c0
if r>0 and r<=N and c>0 and c<=N then
if a$(offset+r, c)="" or a$(offset+r, c)=" " then list$=addUniq$(list$, r;",";c)
end if
addNeighbourFreeList$=list$
end function

function addUniq$(list$, item$)
if instr(" ";list$;" ", " ";item$;" ")=0 then
addUniq$=list$;" ";item$
else
addUniq$=list$
end if
end function

function countItems(list$)
do
i=i+1
w$=word$(list$,i)
loop until w$=""
countItems=i-1
end function

function randomSelect$(list$)
r=randInt1(countItems(list$))
randomSelect$=word$(list$,r)
end function

function randInt(n) '0..n-1
randInt=int(rnd(1)*n)
end function

function randInt1(n) '1..n
randInt1=int(rnd(1)*n)+1
end function


[plus]

This game is definitely played differently than what I am use to.
1. players alternate turns hit or miss
2. you can put ships right next to each other to fool the enemy into wrong thinking but I never played with radar???
3. for positioning ships I suggest va1 or ha1 for v's it's the top and ship goes vertically downward
for h's its the leftmost cell the ships runs horizontal for it's length
4. really would like to see my board before shooting instead of scrolling up to remind myself.

But this is tsh73 version so, thumbs up!

b = b + ...

[plus]

OK tsh73 you've shown me yours and I've shown you mine. Now it's time to compare, no?

I am particularly interested in how you are going about sinking a ship after you get a hit on it.

I started reviewing your subroutines and OMG we are light years different! What is all that?
Helpful would be a quick description of what each routine is supposed to do. Isn't it obvious? no, some are but radar stuff???

Maybe, if you don't mind, a verbal description of what you are doing after a hit is detected maybe I need to know how hits are detected too.
Just some more translation into words if you please. (What coder minds talking about their creations, I don't think I know a single one!)

Of course, if I asked, I have to be prepared to do same for you. Honestly I forgot half the stuff I did when I first created those AI routines.
But I am committed to properly comment the code to make it clearer to others and myself, dang it!, because someone at another forum was complaining about that and I thought it a proper thing to request in earnest motivation.

But I asked you first!

b = b + ...

[tsh73]

Ok
first is data structure
Wikipedia says

The game is played on four grids, two for each player. The grids are typically square – usually 10×10 – and the individual squares in the grid are identified by letter and number.[10] On one grid the player arranges ships and records the shots by the opponent. On the other grid, the player records their own shots.

Let us say N=10
in games I used to play cells numbered from 1, so cells would be a1...j10

So for player 1,
"one grid the player arranges ships and records the shots by the opponent" is actually
a$(1..N,1..N)
Since Basic allocates from 0, I added extra row\column to
a$(0..N+1, 0..N+1)
so neighbour of valid cell did not end in "out of array" error.

But we need "other grid, the player records their own shots"
, and two more grids for player 2.

I chose to make array longer, like
dim a$(200,N+1)  
and use first N rows for player1
N rows after some offset (actually radar=40) to "other grid, the player records their own shots"
(that I call "radar", but it really only memory device for remembering own shots, hits and misses)
and the same for player2, but after own offset (player2=100)

So I have it all in single array, distinguished by row offset
offset 0
. player1=0, no offset - player 1 ships
offset 20
. shadow=20 - rather important in this version that ships could not touch each other. It could be thought of each ship cast "shadow" one cell any direction, so no other ships could occupy that shadowed area.
This part of array used then placing the ships for player 1, only.
offset 40
. radar=40
place for the player1 records their own shots. Also AI marks shadowed cells there (with +).
offset 100
. player2=100, player 2 ships
offset 120
. player2+shadow
This part of array used then placing the ships for player 2, only.
offset 140
. player2+radar
place for the player2 records their own shots. (same for AI, if player 2 is AI)

For my troubles I could use same code for player 1 and player 2
(and actually for diplaying ships map and hits/misses (radar) map).

BTW is player1 is 0 and player2 is 100, then "enemy" is (player2-player) ;)

Now, on with ships
it's interesting but I code ship with repeated symbols, one ship - one symbol (as you did)
But you use digits, and different for player and computer
while I use letters, same letters for player 1 and player 2
Enpty cells are not initialised ("")

Then "player" shoot at (row, col),
. function shoot5$(player)
program checks a$(enemy+row, col)
If it holds "x" or "o" then we already shoot that point (and hit, or miss)
if it empty, program puts "O" on that place
at player radar
. a$(player+radar+r, c)="O"
and at enemy ships map
. a$(enemy+r, c)="O"
Else it remembers letter at that place
. marker$=a$(enemy+r, c)
and puts "X" for hit.
After hit it searches for other accurences of letter
. if countMarker(enemy, marker$)
If there is no more of this letter, it means "kill"
That means we know eaxactly there killed ship is
so we could mark ajacent cells with "+"
I had it rather convoluted -
call mkRadarShadow2 player, r,c
.it calls recursive fill
.. sub paintKilled offset,r,c
'painting "x" with "#"
.Then
.. sub mkRadarShadow2.1 player
.marks all empty neghbours of (#) with (+)
.then it converts all (#) back to (x)
.and restores lat shot big (X)

Now for AI part.
(ha. Most of it is "not shoot twice at place you alreaduy shot" ;)) )
So AI has that "radar" map
and I have this
. dim prevHit$(player2)
actually each player uses single string
prevHit$(player1) and prevHit$(player2)
If it is empty, AI have no idea where to shoot
So it just creates a list of all empty cells (not hit, not shadowed by killed ship) on radar
if  list$="" then
list$=mkFreeList$(player+radar)
end if
and then just take random one
               shoot$=randomSelect$(list$)
r=val(word$(shoot$,1,","))
c=val(word$(shoot$,2,","))
Now if we endeed have a hit
then prevHit$(player) added that hit point (so it stores all hit points of a ship)
(prevHit$(player) gets cleared after kill)

If prevHit$(player) is not empty, AI creates list of possible (empty) nighbours for all cells from prevHit$(player)
. list$=addNeighbourFreeList$(player+radar,r0,c0, list$)
(non-repeating, with
.. ist$=addUniq$(list$, r;",";c))
and then just take random one (with same piece of code as before!)

A would confess, all that list stuff definitely Python influence ;)
But seems working.

Last interesting thing
Then it gets first hit, it has no idea where to shoot next
but it knows for sure that there no ship is possible diagonally, so
. call mkRadarDiagShadow player, r,c
marks radar as this

+ +
X
+ +

So it randomly fires at empty nighbour cell, NESW direction

But after second hit we got something like this

++++
Xx
++++

You see? It gets automatically restricted to a line!

[plus]

yes, and if a miss you have one end closed by "radar" OK

Well the rule of no ships touching makes "the problem' which ship are you hitting with the 2nd hit NOT (a problem at all!)

tsh73 thank you very much for your time in explaining, that clears things up very nicely!



b = b + ...