Add <cassert> header include

This fixes some Linux build failures.

2016/puzzle-10-01.cc

@@ -3,6 +3,7 @@
 //
 
 #include <algorithm>
+#include <cassert>
 #include <iostream>
 #include <regex>
 #include <string>
@@ -129,4 +130,4 @@ auto main() -> int
       bot.clear();
     }
   }
-}
+}