Data update

Task/LZW-compression/Applesoft-BASIC/lzw-compression.basic

@@ -0,0 +1,54 @@
+ 0 PLAIN$ = "TOBEORNOTTOBEORTOBEORNOT"
+ 10  GOSUB 200"ENCODE PLAIN$
+ 20  FOR I = 1 TO  LEN (ENCODE$) STEP 2
+ 30      PRINT S$ ASC ( MID$ (ENCODE$,I)) + 256 *  ASC ( MID$ (ENCODE$,I + 1));
+ 40      LET S$ = " "
+ 50  NEXT
+ 60  PRINT
+ 70  GOSUB 300"DECODE ENCODE$
+ 80  PRINT PLAIN$;
+ 90  END
+
+ 100  FOR C = 0 TO 1E9 STEP 0
+ 110      IF I > S THEN  RETURN
+ 120      FOR D = 1 TO L - 1
+ 130          IF W$ <  > DICT$(D) THEN  NEXT D
+ 140      IF D >  = L THEN  RETURN
+ 150      LET I = I + 1
+ 160      LET W$ = W$ +  MID$ (PLAIN$,I,1)
+ 170      LET C = D
+ 180  NEXT C
+ 190  RETURN
+
+ REM  ENCODE PLAIN$ RETURN ENCODE$
+ 200  IF NOT DI THEN DIM DICT$(4095)
+ 210  FOR I = 0 TO 255:DICT$(I) =  CHR$ (I): NEXT
+ 220  LET DI = 1 : L = I : S =  LEN (PLAIN$):ENCODE$ = ""
+ 230  LET W$ =  LEFT$ (PLAIN$,1)
+ 240  FOR I = 1 TO 1E9 STEP 0
+ 250      GOSUB 100
+ 260      LET DICT$(L) = W$:L = L + 1:W$ =  RIGHT$ (W$,1)
+ 270      LET C% = C / 256:ENCODE$ = ENCODE$ +  CHR$ (C - C% * 256) +  CHR$ (C%)
+ 280      IF I <  = S THEN  NEXT I
+ 290  RETURN
+
+ REM  DECODE ENCODE$ RETURN PLAIN$
+ 300  IF NOT DI THEN DIM DICT$(4095)
+ 310  FOR I = 0 TO 255:DICT$(I) =  CHR$ (I): NEXT
+ 320  LET DI = 1 : L = I
+ 330  FOR I = L TO 4095:DICT$(I) = "": NEXT
+ 340  LET C =  ASC (ENCODE$) + 256 *  ASC ( MID$ (ENCODE$,2))
+ 350  LET W$ = DICT$(C)
+ 360  LET PLAIN$ = W$
+ 370  LET S =  LEN (ENCODE$)
+ 380  IF S < 4 THEN  RETURN
+ 400  FOR I = 3 TO S STEP 2
+ 410      LET C =  ASC ( MID$ (ENCODE$,I)) + 256 *  ASC ( MID$ (ENCODE$,I + 1))
+ 420      IF C < L THEN T$ = DICT$(C)
+ 430      IF C >  = L THEN T$ = W$ +  LEFT$ (W$,1)
+ 440      LET PLAIN$ = PLAIN$ + T$
+ 450      LET DICT$(L) = W$ +  LEFT$ (T$,1)
+ 460      LET L = L + 1
+ 470      LET W$ = T$
+ 480  NEXT
+ 490  RETURN