Truncatable primes: Difference between revisions

Content added Content deleted

Inline

@@ Line 828: / Line 828: @@
 =={{header|Elena}}==
-ELENA 3.2 :
+ELENA 3.4 :
 <lang elena>import system'calendar.
 import extensions.
-const MAXN = 1000000.
+const int MAXN = 1000000.
-extension mathOp
+extension<int> mathOp
 {
-    isPrime
+    bool isPrime
     [
-        int n := self int.
+        if (self < 2) [ ^ false. ].
+        if (self < 4) [ ^ true. ].
-        if (n < 2) [ ^ false. ].
+        if (self mod:2 == 0) [ ^ false. ].
-        if (n < 4) [ ^ true. ].
+        if (self < 9) [ ^ true. ].
-        if (n mod:2 == 0) [ ^ false. ].
+        if (self mod:3 == 0) [ ^ false. ].
-        if (n < 9) [ ^ true. ].
-        if (n mod:3 == 0) [ ^ false. ].
+        int r := self sqrt.
-        int r := n sqrt.
         int f := 5.
         while (f <= r)
         [
-            if ((n mod:f == 0) || (n mod:(f + 2) == 0))
+            if ((self mod:f == 0) || (self mod:(f + 2) == 0))
                 [ ^ false ].
             f := f + 6
         ].
         ^ true
     ]
-    isRightTruncatable
+    bool isRightTruncatable
     [
-        int n := self.
+        while (self != 0)
-        while (n != 0)
         [
-            ifnot (n isPrime)
+            ifnot (self isPrime)
                 [ ^ false ].
-            n := n / 10
+            self := self / 10
         ].
         ^ true.
     ]
-    isLeftTruncatable
+    bool isLeftTruncatable
     [
-        int n := self.
         int tens := 1.
-        while (tens < n)
+        while (tens < self)
             [ tens := tens * 10. ].
-        while (n != 0)
+        while (self != 0)
         [
-            ifnot (n isPrime)
+            ifnot (self isPrime)
                 [ ^ false ].
             tens := tens / 10.
-            n := n - (n / tens * tens)
+            self := self - (self / tens * tens)
         ].
         ^ true
     ]
 }
-program =
+public program
 [
-    var n := MAXN.
+    int n := MAXN.
-    var max_lt := 0.
+    int max_lt := 0.
-    var max_rt := 0.
+    int max_rt := 0.
     while ((max_lt == 0) || (max_rt == 0))
     [
         if(n literal; indexOf:"0" == -1)
         [
-            if ((max_lt == 0) && $(n isLeftTruncatable))
+            if ((max_lt == 0) && (n isLeftTruncatable))
                 [
                     max_lt := n.
                 ].
-            if ((max_rt == 0) && $(n isRightTruncatable))
+            if ((max_rt == 0) && (n isRightTruncatable))
                 [
                     max_rt := n.
                 ].
         ].
         n := n - 1.
     ].
     console printLine("Largest truncable left is ",max_lt).
     console printLine("Largest truncable right is ",max_rt).
-    console readChar.
+    console readChar
-].</lang>
+]</lang>
 {{out}}
 <pre>