tree class representation

Author: ivanmmarkovic

Diff for: README.md

@@ -74,6 +74,7 @@ but it also contains other data structures, algorithms and problems.
 
 ### [Trees]()
 - [List of lists representation]()
+- [Class representation]()
 
 ### [Sorting](https://github.com/ivanmmarkovic/Problem-Solving-with-Algorithms-and-Data-Structures-using-Python/tree/master/sorting)
 - [Bubble sort](https://github.com/ivanmmarkovic/Problem-Solving-with-Algorithms-and-Data-Structures-using-Python/blob/master/sorting/bubble-sort.py)

Diff for: trees/class-representation.py

@@ -0,0 +1,67 @@
+class TreeNode:
+    def __init__(self, key=None, left=None, right=None):
+        self.key = key
+        self.left = left
+        self.right = right
+
+    def insert_root_value(self, key=None):
+        self.key = key
+
+    def insert_left(self, key=None):
+        self.left = TreeNode(key, self.left)
+
+    def insert_right(self, key=None):
+        self.right = TreeNode(key, None, self.right)
+
+    def get_root_value(self):
+        return self.key
+
+    def get_left_child(self):
+        return self.left
+
+    def get_right_child(self):
+        return self.right
+
+
+# Write a function build_tree that returns a tree
+# using the list of lists functions that look like this :
+#      a
+#    /   \
+#   b     c
+#    \   / \
+#     d e   f
+
+
+def build_tree() -> TreeNode:
+    tree: TreeNode = TreeNode('a')
+    tree.insert_right('f')
+    tree.insert_right('c')
+    tree.get_right_child().insert_left('e')
+
+    tree.insert_left('b')
+    tree.get_left_child().insert_right('d')
+
+    return tree
+
+
+binary_tree: TreeNode = build_tree()
+
+
+def print_tree(tree: TreeNode):
+    if tree is not None:
+        print_tree(tree.get_left_child())
+        print(tree.key, end=", ")
+        print_tree(tree.get_right_child())
+
+
+print_tree(binary_tree)
+
+# ['a', 
+#     ['b',
+#         [],
+#         ['d', [], []]],
+#     ['c',
+#         ['e', [], []],
+#         ['f', [], []]
+#     ]
+# ]

Diff for: trees/list-representation.py

@@ -56,7 +56,7 @@ def build_tree() -> list:
 print(binary_tree)
 
 
-# ['a', 
+# ['a',
 #     ['b',
 #         [],
 #         ['d', [], []]],