Data commit

Task/Maze-solving/BBC-BASIC/maze-solving.basic

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+      MazeWidth% = 11
+      MazeHeight% = 9
+      MazeCell% = 50
+
+      VDU 23,22,MazeWidth%*MazeCell%/2+3;MazeHeight%*MazeCell%/2+3;8,16,16,128
+      VDU 23,23,3;0;0;0; : REM Line thickness
+      OFF
+      PROCgeneratemaze(Maze&(), MazeWidth%, MazeHeight%, MazeCell%)
+      PROCsolvemaze(Path{()}, Maze&(), 0, MazeHeight%-1, MazeWidth%-1, 0, MazeCell%)
+      END
+
+      DEF PROCsolvemaze(RETURN s{()}, m&(), x%, y%, dstx%, dsty%, s%)
+      LOCAL h%, i%, n%, p%, q%, w%
+      w% = DIM(m&(),1)
+      h% = DIM(m&(),2)
+      DIM s{(w%*h%) x%,y%}
+      GCOL 3,14
+      m&(x%,y%) OR= &80
+      REPEAT
+        FOR i% = 0 TO 3
+          CASE i% OF
+            WHEN 0: p% = x%-1 : q% = y%
+            WHEN 1: p% = x%+1 : q% = y%
+            WHEN 2: p% = x% : q% = y%-1
+            WHEN 3: p% = x% : q% = y%+1
+          ENDCASE
+          IF p% >= 0 IF p% < w% IF q% >= 0 IF q% < h% IF m&(p%,q%) < &80 THEN
+            IF p% > x% IF m&(p%,q%) AND 1 EXIT FOR
+            IF q% > y% IF m&(p%,q%) AND 2 EXIT FOR
+            IF x% > p% IF m&(x%,y%) AND 1 EXIT FOR
+            IF y% > q% IF m&(x%,y%) AND 2 EXIT FOR
+          ENDIF
+        NEXT
+        IF i% < 4 THEN
+          m&(p%,q%) OR= &80
+          s{(n%)}.x% = x%
+          s{(n%)}.y% = y%
+          n% += 1
+        ELSE
+          IF n% > 0 THEN
+            n% -= 1
+            p% = s{(n%)}.x%
+            q% = s{(n%)}.y%
+          ENDIF
+        ENDIF
+        LINE (x%+0.5)*s%,(y%+0.5)*s%,(p%+0.5)*s%,(q%+0.5)*s%
+        x% = p%
+        y% = q%
+      UNTIL x%=dstx% AND y%=dsty%
+      s{(n%)}.x% = x%
+      s{(n%)}.y% = y%
+      ENDPROC
+
+      DEF PROCgeneratemaze(RETURN m&(), w%, h%, s%)
+      LOCAL x%, y%
+      DIM m&(w%, h%)
+      FOR y% = 0 TO h%
+        LINE 0,y%*s%,w%*s%,y%*s%
+      NEXT
+      FOR x% = 0 TO w%
+        LINE x%*s%,0,x%*s%,h%*s%
+      NEXT
+      GCOL 15
+      PROCcell(m&(), RND(w%)-1, y% = RND(h%)-1, w%, h%, s%)
+      ENDPROC
+
+      DEF PROCcell(m&(), x%, y%, w%, h%, s%)
+      LOCAL i%, p%, q%, r%
+      m&(x%,y%) OR= &40 : REM Mark visited
+      r% = RND(4)
+      FOR i% = r% TO r%+3
+        CASE i% MOD 4 OF
+          WHEN 0: p% = x%-1 : q% = y%
+          WHEN 1: p% = x%+1 : q% = y%
+          WHEN 2: p% = x% : q% = y%-1
+          WHEN 3: p% = x% : q% = y%+1
+        ENDCASE
+        IF p% >= 0 IF p% < w% IF q% >= 0 IF q% < h% IF m&(p%,q%) < &40 THEN
+          IF p% > x% m&(p%,q%) OR= 1 : LINE p%*s%,y%*s%+4,p%*s%,(y%+1)*s%-4
+          IF q% > y% m&(p%,q%) OR= 2 : LINE x%*s%+4,q%*s%,(x%+1)*s%-4,q%*s%
+          IF x% > p% m&(x%,y%) OR= 1 : LINE x%*s%,y%*s%+4,x%*s%,(y%+1)*s%-4
+          IF y% > q% m&(x%,y%) OR= 2 : LINE x%*s%+4,y%*s%,(x%+1)*s%-4,y%*s%
+          PROCcell(m&(), p%, q%, w%, h%, s%)
+        ENDIF
+      NEXT
+      ENDPROC