Data update

Task/Twin-primes/FutureBasic/twin-primes.basic

@@ -0,0 +1,35 @@
+_max = 1000000000
+_size = _max/16 + 16
+uint8 primes(_size)
+
+local fn twins( max as uint64 )
+  CFTimeInterval t : t = fn CACurrentMediaTime
+  uint64 num, p, twins = 0, prev = 0
+
+  for num = 3 to max step 2
+    if primes(num >> 4) & bit((num & 15) >> 1) then continue
+
+    p = num * num
+    while p < max
+      primes(p >> 4) |= bit((p & 15) >> 1)
+      p += num << 1
+    wend
+
+    twins += (num == prev + 2)
+    prev   = num
+  next
+
+  printf @"%10d twin primes in first %d integers   %.3f ms."¬
+  , twins, max, 1000 * (fn CACurrentMediaTime - t)
+end fn
+
+window 1, @"Twin Primes"
+print
+CFTimeInterval tm : tm = fn CACurrentMediaTime
+for byte x = 1 to 9
+  fn memset( @primes(0), 0, _size ) //Clear array for each run
+  fn twins( 10^x )
+next
+printf @"  Total time: %.3f sec.",(fn CACurrentMediaTime - tm)
+
+handleevents