100 PROGRAM "Shuffle.bas"
110 RANDOMIZE
120 NUMERIC ARRAY(1 TO 20)
130 CALL INIT(ARRAY)
140 CALL WRITE(ARRAY)
150 CALL SHUFFLE(ARRAY)
160 CALL WRITE(ARRAY)
170 DEF INIT(REF A)
180   FOR I=LBOUND(A) TO UBOUND(A)
190     LET A(I)=I
200   NEXT
210 END DEF
220 DEF WRITE(REF A)
230   FOR I=LBOUND(A) TO UBOUND(A)
240     PRINT A(I);
250   NEXT
260   PRINT
270 END DEF
280 DEF SHUFFLE(REF A)
290   FOR I=UBOUND(A) TO LBOUND(A) STEP-1
300     LET CARD=RND(UBOUND(A)-LBOUND(A))+LBOUND(A)+1
310     IF CARD<>I THEN LET T=A(CARD):LET A(CARD)=A(I):LET A(I)=T
320   NEXT
330 END DEF