Updated tutorial_gdscript_efficiently (markdown)

tutorial_gdscript_efficiently.md

@@ -163,6 +163,80 @@ use_array(array) # passed as reference
 #freed when no longer in use
 ```
 
+In dynamically typed languages, arrays can also double as other datatypes, such as lists:
+
+```python
+var array = []
+array.append(4)
+array.append(5)
+array.pop_front()
+```
+
+or unordered sets:
+
+```python
+var a = 20
+if a in [10,20,30]:
+	print("We have a Winner!")
+```
+
+### Dictionaries
+
+Dictionaries are always a very powerful in dynamically typed languages. Most programmers that come from statically typed languages (such as C++ or C#) ignore their existence and make their life unnecessarily more difficult. This datatype is generally not present in such languages (or only on limited form).
+
+Dictionaries can map any value to any other value with complete disregard for the datatype used as either key or value. Contrary to popular belief, they are very efficient because they can be implemented with hash tables. They are, in fact, so efficient that languages such as Lua will go as far as implementing arrays as dictionaries. 
+
+Example of Dictionary:
+
+```python
+var d = { "name":"john", "age":22 } # simple syntax
+print("Name: ", d["name"], " Age: ", d["age"] )
+```
+
+Dictionaries are also dynamic, keys can be added or removed at any point at little cost:
+
+```python
+d["mother"]="Rebecca" # addition
+d["age"]=11 # modification
+d.erase("name") #removal
+```
+
+Two-dimensional arrays can often be implemented easier with dictionaries. Here's a simple battleship game example:
+
+```python
+#battleship game
+
+const SHIP=0
+const SHIP_HIT=1
+const WATER_HIT=2
+
+var board={}
+
+func initialize():
+	board[Vector(1,1)]=SHIP
+	board[Vector(1,2)]=SHIP
+	board[Vector(1,3)]=SHIP
+
+func missile(pos):
+
+	if pos in board: #something at that pos
+		if board[pos]==SHIP: #there was a ship! hit it
+			board[pos]=SHIP_HIT
+		else: 
+			print("already hit here!") # hey dude you already hit here
+	else: #nothing, mark as water
+		board[pos]=WATER_HIT
+
+
+func game():
+	initialize()
+	missile( Vector2(1,1) )
+	missile( Vector2(5,8) )
+	missile( Vector2(2,3) )
+
+```
+
+