Rare numbers: Difference between revisions

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@@ Line 1,246: / Line 1,246: @@
 =={{header|FreeBASIC}}==
+Made some changes and added a simple test to speed things up. Results in about 1 minute.
-About 16.5 minutes to find the first 5 rare numbers
 {{trans|Phix}}
-<lang freebasic>#include "string.bi"
+<lang freebasic>Function revn(n As ULongInt, nd As ULongInt) As ULongInt
+    Dim As ULongInt r
-#define floor(x) ((x*2.0-0.5) Shr 1)
+    For i As UInteger = 1 To nd
-#define remainder(n, m) (n-m*Int(n/m))
+        r = r * 10 + n Mod 10
+        n = n \ 10
-Function revn(n As Integer, nd As Integer) As Integer
-    Dim As Integer r = 0
-    For i As Integer = 1 To nd
-        r = r * 10 + remainder(n, 10)
-        n = floor(n/10)
     Next i
     Return r
 End Function
-Dim As Integer nd = 2, count = 0, lim = 99, n = 9
+Dim As UInteger nd = 2, count, lim = 90, n = 20
 Do
     n += 1
-    Dim As Integer r = revn(n,nd)
+    Dim As ULongInt r = revn(n,nd)
     If r < n Then
-        Dim As Integer s = n+r, d = n-r
+        Dim As ULongInt s = n + r, d = n - r
-        If s = (floor(Sqr(s)) ^ 2) And d = (floor(Sqr(d)) ^ 2) Then
+        If nd And 1 Then
+            If d Mod 1089 <> 0 Then GoTo jump
+        Else
+            If s Mod 121 <> 0 Then GoTo jump
+        End If
+        If Frac(Sqr(s)) = 0 And Frac(Sqr(d)) = 0 Then
             count += 1
-            Print count; ":"; n
+            Print count; ": "; n
             If count = 5 Then Exit Do : End If
         End If
     End If
+jump:
     If n = lim Then
-        lim = lim * 10 + 9
+        lim = lim * 10
         nd += 1
+        n = (lim \ 9) * 2
     End If
 Loop
-Sleep</lang>
+Print
+Print "Done"
+Sleep</lang>
+{{out}}
+<pre>1: 65
+: 621770
+: 281089082
+: 2022652202
+: 2042832002</pre>
 =={{header|Go}}==