Changed guard to pragma

Author: marcelweikum

exercises/practice/alphametics/.meta/example.h

@@ -1,5 +1,4 @@
-#ifndef ALPHAMETICS_H
-#define ALPHAMETICS_H
+#pragma once
 
 #include <optional>
 #include <map>
@@ -9,6 +8,4 @@ namespace alphametics {
 
     std::optional<std::map<char,int>> solve(const std::string& puzzle);
 
-} // namespace alphametics
-
-#endif // ALPHAMETICS_H
+} // namespace alphametics