21 game
21 is a two player game, the game is played by choosing a number (1, 2, or 3) to be added to the running total.
The game is won when the running total reaches exactly 21.
The running total starts at zero.
One player will be the computer. Players alternate supplying a number to be added to the running total.
- Task
Write a computer program that will:
- do the prompting (or provide a button menu),
- check for errors and display appropriate error messages,
- do the additions (add a number to the running total),
- display the running total,
- provide a mechanism for the player to quit/exit/halt/stop/close the program,
- issue a notification when there is a winner, and
- determine who goes first (possibly a random choice, or it can be specified when the game begins).
Phix
If the computer goes first you cannot win.
Once the computer stops displaying "no clear strategy" you cannot win.
The computer_first flag only applies to the first game. After winning, losing, or conceding, you go first.
<lang Phix>bool computer_first = false
bool show_spoiler = false
integer total = 0
procedure computer_play()
integer move = 0
for i=1 to 3 do
if mod(total+i,4)=1 then
move = i
exit
end if
end for
if move=0 then
puts(1,"no clear strategy\n")
move = rand(min(3,21-total))
end if
printf(1,"Total is %d. I play %d.\n",{total,move})
total += move
if total=21 then
puts(1,"21! I win!\n")
end if
end procedure
puts(1,"\n21 game\n\n") puts(1,"Press escape or q to quit the game, c to concede and start a new game from 0\n\n")
if computer_first then
printf(1,"Total is %d.\n",{total})
computer_play()
elsif show_spoiler then
-- The secret to winning!
puts(1,sq_sub("Uif!pomz!xbz!up!xjo!jt!qmbz!2!gjstu-!uifo!5.=dpnqvufs!npwf?!fwfsz!ujnf",1)&"\n\n")
end if
while 1 do
printf(1,"Total is %d. enter 1, 2, or 3: ",{total})
integer ch = wait_key()
puts(1,iff(ch=#1B?"esc":ch)&"\n")
if ch>='1' and ch<='3' then
ch -= '0'
if total+ch>21 then
puts(1,"Too big\n")
else
total += ch
if total=21 then
puts(1,"21! You win!\n")
else
computer_play()
end if
end if
elsif ch=#1B or lower(ch)='q' then
puts(1,"Quitting\n")
exit
end if
if lower(ch)='c' or total=21 then
total = 0
end if
end while</lang>
- Output:
21 game Press escape or q to quit the game, c to concede and start a new game from 0 Total is 0. enter 1, 2, or 3: 1 no clear strategy Total is 1. I play 3. Total is 4. enter 1, 2, or 3: 1 no clear strategy Total is 5. I play 1. Total is 6. enter 1, 2, or 3: 3 no clear strategy Total is 9. I play 1. Total is 10. enter 1, 2, or 3: 1 Total is 11. I play 2. Total is 13. enter 1, 2, or 3: 3 Total is 16. I play 1. Total is 17. enter 1, 2, or 3: 2 Total is 19. I play 2. 21! I win! Total is 0. enter 1, 2, or 3: q Quitting
REXX
Around half of the REXX program deals with incorrect or missing input (of the required integer). <lang rexx>/*REXX program plays the 21 game with a human, each player chooses 1, 2, or 3 which */ /*──────────── is added to the current sum, the first player to reach exactly 21 wins.*/ sep= copies('─', 8); sep2= " "copies('═', 8)" " /*construct an eye─catching msg fences.*/ say sep 'Playing the 21 game.' /*tell what's happening here at the zoo*/ high= 3 /*the highest integer that can be used.*/ g= 21 /*the game target (winning total/sum.*/ $= 0 /*the sum (so far). */
do j=1 while $<g; ok= 1 /*obtain optional move from ARG or ask.*/
low = (j \== 1) /*allow user to choose computer go 1st.*/
say; say sep 'Please enter a number from ' low " ───► 3 (or Quit):"
if j==1 then say sep '[A value of 0 (zero) means you want the computer to go first.]'
pull x _ . 1 ax /*obtain an answer; so far, so good. */
if x= then call ser "Nothing entered."
if _\== then call ser "Too many arguments entered: " ax
if abbrev('QUIT', x, 1) then do; say; say sep "quitting."; exit; end
if \datatype(x, 'N') then call ser "Argument isn't numeric: " x
if \datatype(x, 'W') then call ser "Number isn't an integer: " x
if x<0 then call ser "Number can't be negative: " x
if x=0 & j \== 1 then call ser "Number can't be zero: " x
if x>high then call ser "Number is too large (>"high'): ' x
if \ok then iterate /*Had an error? Then get another number*/
x= x/1 /*normalize the X number; +2 001 3. */
if $+x > g then call ser "Number will cause the sum to exceed " g': ' x
if x\==0 then call tot x, 1 /*0? User wants computer to go first.*/
if $==g then leave /*the user won the game with the last #*/
if $>=g-3 then y= g - $ /*choose a winning number to add to $. */
else y= 1 /* " " minimum " " " " " */
say sep 'The computer chooses ' y " as it's choice."
call tot y, 0
end /*j*/
say if who then say sep 'Congratulations! You have won the 21 game.'
else say sep 'The computer has won the 21 game.'
exit /*stick a fork in it, we're all done. */ /*──────────────────────────────────────────────────────────────────────────────────────*/ ser: if \ok then return; ok=0; er= sep '***error***'; say /*set some literals. */
say; say er arg(1); say; ok=0; return /*say errMsg; set ¬OK.*/
/*──────────────────────────────────────────────────────────────────────────────────────*/ tot: arg q,who; $=$+q; say sep 'The game total is now' sep2 $ sep2; return /*add; show $*/</lang>
- output:
──────── Playing the 21 game. ──────── Please enter a number from 1 ───► 3 (or Quit): ──────── [A value of 0 (zero) means you want the computer to go first.] 3 ◄■■■■■■■■■■ user input ──────── The game total is now ════════ 3 ════════ ──────── The computer chooses 1 as it's choice. ──────── The game total is now ════════ 4 ════════ ──────── Please enter a number from 1 ───► 3 (or Quit): 3 ◄■■■■■■■■■■ user input ──────── The game total is now ════════ 7 ════════ ──────── The computer chooses 1 as it's choice. ──────── The game total is now ════════ 8 ════════ ──────── Please enter a number from 1 ───► 3 (or Quit): 3 ◄■■■■■■■■■■ user input ──────── The game total is now ════════ 11 ════════ ──────── The computer chooses 1 as it's choice. ──────── The game total is now ════════ 12 ════════ ──────── Please enter a number from 1 ───► 3 (or Quit): 3 ◄■■■■■■■■■■ user input ──────── The game total is now ════════ 15 ════════ ──────── The computer chooses 1 as it's choice. ──────── The game total is now ════════ 16 ════════ ──────── Please enter a number from 1 ───► 3 (or Quit): 1 ◄■■■■■■■■■■ user input ──────── The game total is now ════════ 17 ════════ ──────── The computer chooses 1 as it's choice. ──────── The game total is now ════════ 18 ════════ ──────── Please enter a number from 1 ───► 3 (or Quit): 3 ◄■■■■■■■■■■ user input ──────── The game total is now ════════ 21 ════════ ──────── Congratulations! You have won the 21 game.
Ring
<lang ring>
- Project : 21 Game
load "guilib.ring"
limit = 21 posold = 0 button = list(limit) mynum = list(3) yournum = list(3)
new qapp
{
win1 = new qwidget() {
setwindowtitle("21 Game")
setgeometry(100,100,1000,600)
label1 = new qlabel(win1) {
setgeometry(10,10,1000,600)
settext("")
}
label2 = new qlabel(win1) {
setgeometry(240,50,120,40)
setAlignment(Qt_AlignHCenter)
setFont(new qFont("Verdana",12,100,0))
settext("my number:")
}
label3 = new qlabel(win1) {
setgeometry(640,50,120,40)
setAlignment(Qt_AlignHCenter)
setFont(new qFont("Verdana",12,100,0))
settext("your number:")
}
for p = 1 to 3
mynum[p] = new qpushbutton(win1) {
setgeometry(200+p*40,100,40,40)
setstylesheet("background-color:orange")
settext(string(p))
setclickevent("choose(" + string(p) + ",1)")
}
next
for p = 1 to 3
yournum[p] = new qpushbutton(win1) {
setgeometry(600+p*40,100,40,40)
setstylesheet("background-color:white")
settext(string(p))
setclickevent("choose(" + string(p) + ",2)")
}
next
for n = 1 to limit
button[n] = new qpushbutton(win1) {
setgeometry(40+n*40,190,40,40)
settext(string(n))
}
next
show()
}
exec()
}
func choose(ch,ym)
pos = posold + ch
if pos > limit
msg = "You must choose number from 1 to " + string(limit - posold)
msgBox(msg)
for n = 1 to 3
mynum[n].setenabled(false)
yournum[n].setenabled(false)
next
return
ok
for n = posold+1 to pos
if ym = 1
button[n] { setstylesheet("background-color:orange") }
else
button[n] { setstylesheet("background-color:white") }
ok
next
posold = pos
if ym = 1
for n = 1 to 3
mynum[n].setenabled(false)
yournum[n].setenabled(true)
next
else
for n = 1 to 3
mynum[n].setenabled(true)
yournum[n].setenabled(false)
next
ok
if pos = 21
if ym = 1
msgBox("I won!")
else
msgBox("You won!")
ok
ok
func msgBox(text) { m = new qMessageBox(win1) { setWindowTitle("21 Game") setText(text) show() }
}
</lang>
Output:
21 Game
