all tasks

Task/Sorting-algorithms-Permutation-sort/BBC-BASIC/sorting-algorithms-permutation-sort.bbc

@@ -0,0 +1,45 @@
+      DIM test(9)
+      test() = 4, 65, 2, 31, 0, 99, 2, 83, 782, 1
+
+      perms% = 0
+      WHILE NOT FNsorted(test())
+        perms% += 1
+        PROCnextperm(test())
+      ENDWHILE
+      PRINT ;perms% " permutations required to sort "; DIM(test(),1)+1 " items."
+      END
+
+      DEF PROCnextperm(a())
+      LOCAL last%, maxindex%, p%
+      maxindex% = DIM(a(),1)
+      IF maxindex% < 1 THEN ENDPROC
+      p% = maxindex%-1
+      WHILE a(p%) >= a(p%+1)
+        p% -= 1
+        IF p% < 0 THEN
+          PROCreverse(a(), 0, maxindex%)
+          ENDPROC
+        ENDIF
+      ENDWHILE
+      last% = maxindex%
+      WHILE a(last%) <= a(p%)
+        last% -= 1
+      ENDWHILE
+      SWAP a(p%), a(last%)
+      PROCreverse(a(), p%+1, maxindex%)
+      ENDPROC
+
+      DEF PROCreverse(a(), first%, last%)
+      WHILE first% < last%
+        SWAP a(first%), a(last%)
+        first% += 1
+        last% -= 1
+      ENDWHILE
+      ENDPROC
+
+      DEF FNsorted(d())
+      LOCAL I%
+      FOR I% = 1 TO DIM(d(),1)
+        IF d(I%) < d(I%-1) THEN = FALSE
+      NEXT
+      = TRUE