Data update

Task/Rare-numbers/EasyLang/rare-numbers.easy

@@ -0,0 +1,20 @@
+fastfunc next n .
+   while 1 = 1
+      n += 1
+      h = n
+      nrev = 0
+      while h > 0
+         nrev = nrev * 10 + h mod 10
+         h = h div 10
+      .
+      if sqrt (n + nrev) mod 1 = 0
+         if n - nrev >= 1 and sqrt (n - nrev) mod 1 = 0
+            return n
+         .
+      .
+   .
+.
+for cnt to 5
+   n = next n
+   print n
+.

Task/Rare-numbers/Lua/rare-numbers.lua

@@ -0,0 +1,46 @@
+do  -- find the first five rare numbers
+
+    local function revn ( na )
+        local n, r = na, 0
+        while n > 0 do
+            r = r * 10   r = r + ( n % 10 )
+            n = math.floor( n / 10 )
+        end
+        return r
+    end -- revn
+
+    local nd, count, lim, n = 2, 0, 90, 20
+    local oddNd = nd % 2 == 1
+    while true do
+        n = n + 1
+        local r = revn( n )
+        if  r < n then
+            local s, d = n + r, n - r
+            local tryThis = false
+            if   oddNd
+            then tryThis = d % 1089 == 0
+            else tryThis = s %  121 == 0
+            end
+            if tryThis then
+                local rootS = math.sqrt( s )
+                if  rootS == math.floor(rootS )
+                then
+                    local rootD = math.sqrt( d )
+                    if    rootD == math.floor( rootD )
+                    then
+                        count = count + 1
+                        io.write( count, ": ", n, "\n" )
+                        if count >= 5 then os.exit() end
+                    end
+                end
+            end
+            if  n == lim
+            then
+                lim   = lim * 10
+                nd    = nd  +  1
+                oddNd = not oddNd
+                n     = math.floor( lim / 9 ) * 2
+            end
+        end
+    end
+end