Initial data commit

Task/Permutations/BBC-BASIC/permutations.basic

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+      DIM List%(3)
+      List%() = 1, 2, 3, 4
+      FOR perm% = 1 TO 24
+        FOR i% = 0 TO DIM(List%(),1)
+          PRINT List%(i%);
+        NEXT
+        PRINT
+        PROC_NextPermutation(List%())
+      NEXT
+      END
+
+      DEF PROC_NextPermutation(A%())
+      LOCAL first, last, elementcount, pos
+      elementcount = DIM(A%(),1)
+      IF elementcount < 1 THEN ENDPROC
+      pos = elementcount-1
+      WHILE A%(pos) >= A%(pos+1)
+        pos -= 1
+        IF pos < 0 THEN
+          PROC_Permutation_Reverse(A%(), 0, elementcount)
+          ENDPROC
+        ENDIF
+      ENDWHILE
+      last = elementcount
+      WHILE A%(last) <= A%(pos)
+        last -= 1
+      ENDWHILE
+      SWAP A%(pos), A%(last)
+      PROC_Permutation_Reverse(A%(), pos+1, elementcount)
+      ENDPROC
+
+      DEF PROC_Permutation_Reverse(A%(), first, last)
+      WHILE first < last
+        SWAP A%(first), A%(last)
+        first += 1
+        last -= 1
+      ENDWHILE
+      ENDPROC