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Task/100-doors/GFA-Basic/100-doors.gfa

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+'
+' 100 doors problem
+'
+DIM doors!(101) ! use indices 1 to 100
+@close_doors
+@do_passes
+@show_doors
+'
+PROCEDURE close_doors
+  ARRAYFILL doors!(),FALSE
+RETURN
+'
+PROCEDURE do_passes
+  LOCAL i%,j%
+  FOR i%=1 TO 100
+    FOR j%=i% TO 100 STEP i%
+      doors!(j%)=NOT doors!(j%)
+    NEXT j%
+  NEXT i%
+RETURN
+'
+PROCEDURE show_doors
+  LOCAL i%
+  OPENW 1
+  CLEARW 1
+  FOR i%=1 TO 100
+    IF doors!(i%)
+      PRINT "Door ";i%;" is open"
+    ENDIF
+  NEXT i%
+  PRINT "(press a key to end program)"
+  ~INP(2)
+  CLOSEW 1
+RETURN