Merge pull request #1 from KingFredrickVI/master

Python for Tree Traversal

Author: leios

chapters/fundamental_algorithms/tree_traversal.md

@@ -114,6 +114,8 @@ Do you think we should be using real code snippets in the main text or stick the
 
 # Example Code
 
+### C++
+
 ```cpp
 /*-------------simple_tree_traversal.cpp--------------------------------------//
 *
@@ -213,3 +215,81 @@ int main(){
 }
 
 ```
+
+### Python
+
+```Python
+
+# /*-------------simple_tree_traversal.py--------------------------------------//
+# *
+# * Purpose: To implement basic tree traversal in Python.
+# *
+# * Run: python simple_tree_traversal.py
+# *
+# *-----------------------------------------------------------------------------*/
+
+
+class Node:
+
+    def __init__(self):
+        self.data = None
+        self.children = []
+
+
+def create_tree(node, num_row, num_child):
+    node.data = num_row
+
+    if num_row > 0:
+        for i in range(num_child):
+            child = create_tree(Node(), num_row-1, num_child)
+            node.children.append(child)
+
+    return node
+
+def DFS_recursive(node):
+    if len(node.children) > 0:
+        print node.data
+
+        for child in node.children:
+            DFS_recursive(child)
+
+def DFS_stack(node):
+    stack = []
+    stack.append(node)
+
+    temp = None
+
+    while len(stack) > 0:
+        print stack[-1].data
+        temp = stack.pop()
+
+        for child in temp.children:
+            stack.append(child)
+
+def BFS_queue(node):
+    queue = []
+    queue.append(node)
+
+    temp = None
+
+    while len(queue) > 0:
+        print queue[0].data
+        temp = queue.pop(0)
+
+        for child in temp.children:
+            queue.append(child)
+
+def main():
+    tree = create_tree(Node(), 3, 3)
+
+    print "Recursive:"
+    DFS_recursive(tree)
+
+    print "Stack:"
+    DFS_stack(tree)
+
+    print "Queue:"
+    BFS_queue(tree)
+
+main()
+```