Add solution sheet9

aufgaben/sheet9/sol3/map.rs

@@ -0,0 +1,15 @@
+
+macro_rules! hash_map {
+    ( $($key:expr => $value:expr ,)* ) => {{
+        let mut map = ::std::collections::HashMap::new();
+        $( map.insert($key, $value); )*
+        map
+    }};
+    ( $($key:expr => $value:expr),* ) => { hash_map!($($key => $value ,)*) };
+}
+
+
+fn main() {
+    let ages = hash_map!{ "Sabine" => 26, "Peter" => 32 };
+    println!("{:#?}", ages);
+}