100 PROGRAM "RemoveDu.bas"
110 RANDOMIZE
120 NUMERIC ARR(1 TO 20),TOP
130 LET TOP=FILL(ARR)
140 CALL WRITE(ARR,TOP)
150 LET TOP=REMOVE(ARR)
160 CALL WRITE(ARR,TOP)
170 DEF WRITE(REF A,N)
180   FOR I=1 TO N
190     PRINT A(I);
200   NEXT
210   PRINT
220 END DEF
230 DEF FILL(REF A)
240   LET FILL=UBOUND(A):LET A(LBOUND(A))=1
250   FOR I=LBOUND(A)+1 TO UBOUND(A)
260     LET A(I)=A(I-1)+RND(3)
270   NEXT
280 END DEF
290 DEF REMOVE(REF A)
300   LET ST=0
310   FOR I=LBOUND(A)+1 TO UBOUND(A)
320     IF A(I-1)=A(I) THEN LET ST=ST+1
330     IF ST>0 THEN LET A(I-ST)=A(I)
340   NEXT
350   LET REMOVE=UBOUND(A)-ST
360 END DEF