Make nsieve fair. Solves hanabi1224#419

Author: HFTrader

bench/algorithm/nsieve/3.cpp

@@ -0,0 +1,46 @@
+
+// The Computer Language Shootout
+// http://shootout.alioth.debian.org/
+// Precedent C entry modified by bearophile for speed and size, 31 Jan 2006
+// Converted to C++ by Paul Kitchin
+
+#include <iomanip>
+#include <iostream>
+#include <sstream>
+#include <vector>
+
+void nsieve(std::size_t max) {
+  std::vector<bool> flags(max,false);
+  std::size_t count = 0;
+  for (std::size_t value = 2; value < max; ++value) {
+    if (!flags[value]) {
+      ++count;
+      for (std::size_t multiple = value * 2; multiple < max;
+           multiple += value) {
+        flags[multiple] = true;
+      }
+    }
+  }
+  std::cout << "Primes up to " << std::setw(8) << max << ' ' << std::setw(8)
+            << count << '\n';
+}
+
+int main(int argc, char **argv) {
+  if (argc != 2) {
+    std::cerr << "usage: " << argv[0] << " <n>\n";
+    return 1;
+  }
+  unsigned int count;
+  {
+    std::istringstream convertor(argv[1]);
+    if (!(convertor >> count) || !convertor.eof()) {
+      std::cerr << "usage: " << argv[0] << " <n>\n";
+      std::cerr << "\tn must be an integer\n";
+      return 1;
+    }
+  }
+  for (std::size_t i = 0; i < 3; ++i) {
+    nsieve(10000 << (count - i));
+  }
+}
+

bench/bench_cpp.yaml

@@ -18,6 +18,7 @@ problems:
   - name: nsieve
     source:
       - 1.cpp
+      - 3.cpp
 compiler_version_command:
 compiler_version_regex:
 runtime_version_parameter: