Added previous arduino implementations.

Problem1.cpp

@@ -0,0 +1,21 @@
+#include "Problem1.hpp"
+
+Problem1::Problem1() {
+  input = 1000;
+}
+
+bool Problem1::Step() {
+  // add all factors of 3 under input
+  factor3 += 3;
+  if (factor3 < input) output += factor3;
+
+  // add all factors of 5 under input but skip factors of 3
+  factor5 += 5;
+  if (factor5 < input) {
+    factor5_tick++;
+    if (factor5_tick != 3) output += factor5;
+    else factor5_tick = 0;
+  }
+
+  return input < factor3 && input < factor5;
+}