tasks a-s

Task/Permutations-Derangements/PureBasic/permutations-derangements-2.purebasic

@@ -0,0 +1,57 @@
+Procedure.i deranged(depth,lenn,array d(1),show)
+Protected count.l,tmp,i
+        if (depth = lenn)
+                if (show)
+                        ; for i = 0 to lenn-1:so(chr(d(i) + 'a')):next
+                        for i = 0 to lenn-1:Debug chr(d(i) + 'a'):next
+                        ; cw("")
+                        Debug ""
+                endif
+                ProcedureReturn  1
+        endif
+
+        for i = lenn - 1 to depth step -1
+                if i = d(depth) :continue:endif
+
+                tmp = d(i): d(i) = d(depth): d(depth) = tmp
+                count + deranged(depth + 1, lenn, d(), show)
+                tmp = d(i): d(i) = d(depth): d(depth) = tmp
+        next
+
+ProcedureReturn count
+EndProcedure
+
+Procedure.q sub_fact(n)
+if n=0:ProcedureReturn 1:endif
+if n=1:ProcedureReturn 0:endif
+ProcedureReturn (sub_fact(n-1)+sub_fact(n-2))*(n-1)
+EndProcedure
+
+Procedure.i gen_n(n,show)
+Protected r.i
+global dim a(1024)
+for i=0 to n-1:a(i)=i:next
+ProcedureReturn  deranged(0, n, a(), show)
+EndProcedure
+
+        ; cw("Deranged Four:")
+        Debug "Deranged Four:"
+        gen_n(4, 1)
+        ; cw("")
+        Debug ""
+
+        ; cw("Compare list vs calc:")
+        Debug "Compare list vs calc:"
+        for i = 0 to 9
+                ; cw(str(i)+" "+str(gen_n(i, 0))+" "+str(sub_fact(i)))
+                Debug str(i)+" "+str(gen_n(i, 0))+" "+str(sub_fact(i))
+        next
+        ; cw("")
+        Debug ""
+
+        ; cw("further calc:")
+        Debug "further calc:"
+        for i = 10 to 20
+                ; cw(str(i)+" "+str(sub_fact(i)))
+                Debug str(i)+" "+str(sub_fact(i))
+        next