10REM "B.SHELL" 20REM SHELL SORT 30REM HARD TO UNDERSTAND 40: 50MODE7:VDU23;8202;0;0;0; 60@%=&50506 70ONERRORREPORT:PRINT" at line ";ERL: END 80pass%=0 90size%=20 100max%=40 110seed%=1 120DIMA%(size%) 130PROCrandomize 140PROCshell`sort 150PRINTCHR$(11)+" Sorted." 160END 170: 180DEFPROCrandomize 190seed%=RND(-seed%) 200FOR loop%=0 TO size% 210A%(loop%)=RND(max%) 220NEXT loop% 230PROCshowdata 240ENDPROC 250: 260DEFPROCshowdata 270CLS:PRINT" Shell sort routine."'" Pass number ";pass%; 280IF pass%=0 THEN PRINT" Initial stat e." ELSE PRINT 290FOR loop%=0 TO size% 300PRINTA%(loop%) 310NEXT loop% 320PRINT" <SPACE>" 330REPEAT:A=GET:UNTIL A=32 340ENDPROC 350: 360DEFPROCshell`sort 370counter%=size% 380REPEAT 390pass%=pass%+1 400counter%=counter% DIV 2 410FOR loop%=0 TO size%-counter% 420low%=loop% 430high%=counter%+loop% 440REPEAT 450flag=FALSE 460IF A%(high%)>A%(low%) THEN swap%=A% (low%):A%(low%)=A%(high%):A%(high%)=swap %:high%=low%:low%=low%-counter%:flag=TRU E 470UNTIL (flag=FALSE) OR (low%<=0) 480NEXT loop% 490PROCshowdata 500UNTIL counter%<=0 510ENDPROC