Added BFS

Breadth First Search.py

@@ -0,0 +1,87 @@
+class Node:
+  def __init__(self,val):
+    self.val = val
+    self.left = None
+    self.right = None
+
+class BinarySearchTree:
+  def __init__(self):
+    self.root = None
+
+  def insert(self,val):
+    new_node = Node(val)
+    if self.root == None:
+      self.root = new_node
+      return 
+    temp = self.root
+    while True:
+      if new_node.val < temp.val:
+        if temp.left == None:
+          temp.left = new_node
+          break
+        else:
+          temp = temp.left
+      elif new_node.val > temp.val:
+        if temp.right == None:
+          temp.right = new_node
+          break
+        else:
+          temp = temp.right
+
+  def lookup(self,val):
+    temp = self.root
+    while True:
+      if temp.val == val:
+        return True
+      elif temp == None:
+        return False
+      elif val < temp.val:
+        temp = temp.left
+      elif val > temp.val:
+        temp = temp.right
+
+  def breadthfirstsearch(self):
+    currnode = self.root
+    mylist = []
+    queue = []
+    queue.append(currnode)
+
+    while len(queue) > 0:
+      currnode = queue[0]
+      del queue[0]
+      mylist.append(currnode.val)
+      if currnode.left:
+        queue.append(currnode.left)
+      if currnode.right:
+        queue.append(currnode.right)
+
+    return mylist
+
+  def recursivebfs(self,queue,mylist):
+    if len(queue) == 0:
+      return mylist
+    currnode = queue[0]
+    del queue[0]
+    mylist.append(currnode.val)
+    if currnode.left:
+      queue.append(currnode.left)
+    if currnode.right:
+      queue.append(currnode.right)
+
+    return self.recursivebfs(queue,mylist)
+
+
+
+tree = BinarySearchTree()
+tree.insert(9)
+tree.insert(4)
+tree.insert(6)
+tree.insert(20)
+tree.insert(170)
+tree.insert(15)
+tree.insert(1)
+
+x = tree.lookup(170)
+print(x)  
+print(tree.breadthfirstsearch())
+print(tree.recursivebfs([tree.root],[]))