Atari 400 Basic Reference Manual page 102

BUBBLE SORT
This program uses the string comparison operator"<=" that orders strings ac-
cording to the AT ASCII values of the various characters. Since Atari BASIC does
not have arrays of strings, all the strings used in this program are actually
substrings of one large string. A bubble sort, though relatively slow ifthere are
a lot of items to be stored, is easy to write, fairly short, and simpler to under-
stand than more complex sorts.
10 DU1 8$( 1)
~'0 GRAPHICS 0 : ?
.
·~
II
..
STF.: I t·lG
:;o
RT"
=?
30 TRAP 30=?
:7
11
Ent.er· ifta>::iiltl_.liil
str·lns le
ngth
11
; :
H~PUT ~tEt-l:
SLEf-H=SLHl-1
35 IF SLHl< 1 OR HlTC3LHD< >SLHl THHi ?
II
PLEASE Et-HEP A P03 IT I!.}£ I t·HEGEP
>
0 . 11
:
GO
TO 30
40
TRAP
40: ? =?
"Enter·
111a>:: l
iftlAiit nt.lfftbe;-·
of
ent.r· ies . "
41 ?
!I (
Entr·
.i es
l.(ih
.i d-,
are shor·t.er· than t.h
e
tna;dt'itUfft
'.•.till be t=·added ' - 'JiU-, blanks . )
II
42 INPJJT
ENT~~ I ES
45 IF HHF.~IE:3<2 Of;~ IHT( Ef.~TPIE::;
> <
>Hm~:IE: : ;
THEt·l ? 11 PLEASE HHER A POSIT I lJE I
r~TEGER
>
1. 11
=GOTO 40
47 TRAP 40(10~)
50 Dit1 A$( :3LEt·t;;(ENT~~ IE~:; ),, iEt· 1 F'$( ~:t
. .
Et·i)
60 ? : ? "Enter· st.r-
.i .
n::.s •:.ne at a
t.
i
1ne .
u
70 ? "Enter·
e111Ph.t
str· in::;.
!.•.ih~n
done (
.iust.
hi t.~:ETUPr·i
>.
II
75 ·? :? 11 PLEA:3E
STAt·~D
8\"'
~~JHILE
THE
:3TRii·~
GS ARE BE I r·~G CLEAPED . . . " .;
80 FOF~ I =1 TO SLEf-t:;~Ef·~TPIE::; :
A!.( I . ' I
>=u ":
t·~
E::<T I
85 ·? :?
90 I=l
101-) FOP .J=l TO HlTRIE::;
110
? "#" , ; , J ;
II II; :
HlPUT TH1P$
120 IF LEN( TEt-1P$ )=0 THEf· i
Et· ~ T~:IE::;=
. ...l-1: GOT
0 190
130 A$( I .. I +::;LB·i 1
)=
TEt'iP$
140 I= I
+::;LEt-4
150
~lE:-=:T
J
190 ? :? :? "PLEASE ~:TAr·[!
E:\'
1·~HILE THE ~::
TR!HGS ARE BEWG :::OF.:TEO ...
II ,;
200
GOSUB
1000 : REt·1 CALL
SOF~T
ROUT
H-IE
202
·? :?
205 I=l
210 FOR K=l TO
Etn~~IE:::
220? "#";K;"
";A$(!,I+SLEN1)
225 I= I +SLD·i
230 NE:=<T K
24€1 TRAP 330 : · - ; - - :? "WOULD YOU LIKE A PR Hi
Appendix H-5