Euler 1-5

project_euler/problem2.cc

@@ -0,0 +1,31 @@
+#include <cstdint>
+#include <fmt/format.h>
+
+std::int64_t fibonacci()
+{
+    static std::int64_t first = 1;
+    static std::int64_t second = 2;
+
+    std::int64_t result = first + second;
+    std::swap(first, second);
+    second = result;
+
+    return result;
+}
+
+int main()
+{
+    std::int64_t result = 2;
+
+    while (true)
+    {
+        std::int64_t value = fibonacci();
+        if (value >= 4'000'000)
+            break;
+        
+        if (value % 2 == 0)
+            result += value;
+    }
+
+    fmt::print("Result: {}\n", result);
+}