Knight's tour: Difference between revisions

<lang ANSI Standard BASIC>100 DECLARE EXTERNAL FUNCTION FNchoosemove

120 PUBLIC NUMERIC X, Y, TRUE, FALSE

130 LET TRUE = -1

140 LET FALSE = 0

160 SET WINDOW 1,512,1,512

170 SET AREA COLOR "black"

180 FOR x=0 TO 512-128 STEP 128

190 FOR y=0 TO 512-128 STEP 128

200 PLOT AREA:x+64,y;x+128,y;x+128,y+64;x+64,y+64

210 PLOT AREA:x,y+64;x+64,y+64;x+64,y+128;x,y+128

220 NEXT y

230 NEXT x

250 SET LINE COLOR "red"

260 SET LINE width 4

280 PUBLIC NUMERIC Board(0 TO 7,0 TO 7)

290 LET X = 0

300 LET Y = 0

310 LET Total = 0

320 DO

330 LET Board(X,Y) = TRUE

340 IF Total <> 0 THEN PLOT LINES: X*64+32,Y*64+32; ELSE PLOT LINES: X*64+32,Y*64+32

350 LET Total = Total + 1

360 LOOP UNTIL FNchoosemove = 0

370 IF Total <> 64 THEN STOP

410 DECLARE EXTERNAL FUNCTIONSUB FNchoosemovePROCtrymove

440 CALL PROCtrymove(X+1, Y+-2, M, newx, newy)

450 CALL PROCtrymove(X+-1, Y-+2, M, newx, newy)

460 CALL PROCtrymove(X-1, Y+-2, M, newx, newy)

470 CALL PROCtrymove(X-1+2, Y-2+1, M, newx, newy)

480 CALL PROCtrymove(X+2, Y+-1, M, newx, newy)

490 CALL PROCtrymove(X+-2, Y-+1, M, newx, newy)

500 CALL PROCtrymove(X-2, Y+-1, M, newx, newy)

560 LET XY = newxnewy

570 LET YFNchoosemove = newyTRUE

DECLARE630 EXTERNAL FUNCTIONIF FNvalidmove(X,Y) = 0 THEN EXIT SUB

640 IF FNvalidmove(X+1,Y+2) =<> 0 THEN EXITLET N = N + SUB1

650 IF FNvalidmove(X+1,Y+-2) <> 0 THEN LET N = N + 1

660 IF FNvalidmove(X+-1,Y-+2) <> 0 THEN LET N = N + 1

670 IF FNvalidmove(X-1,Y+-2) <> 0 THEN LET N = N + 1

680 IF FNvalidmove(X-1+2,Y-2+1) <> 0 THEN LET N = N + 1

690 IF FNvalidmove(X+2,Y+-1) <> 0 THEN LET N = N + 1

700 IF FNvalidmove(X+-2,Y-+1) <> 0 THEN LET N = N + 1

710 IF FNvalidmove(X-2,Y+-1) <> 0 THEN LET N = N + 1

720 IF FNvalidmove(X-2,Y-1) <N> 0M THEN LET N = N +EXIT 1SUB

730 IF N>=M AND RND<.5 THEN EXIT SUB

750 LET Mnewx = NX

760 LET newxnewy = X Y