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1 | 1 | #!/usr/bin/python  | 
2 | 2 | 
 
  | 
3 |  | -__author__ = "Mari Wahl"  | 
4 |  | - | 
 | 3 | +__author__ = "bt3"  | 
5 | 4 | 
 
  | 
6 | 5 | 
 
  | 
7 |  | -from binary_tree import NodeBT, BinaryTree  | 
 | 6 | +class Node(object):  | 
8 | 7 | 
 
  | 
 | 8 | +    def __init__(self, item=None,):  | 
9 | 9 | 
 
  | 
10 |  | -class NodeBST(NodeBT):  | 
11 |  | - | 
12 |  | -    def __init__(self, item=None, level=0):  | 
13 | 10 |         self.item = item  | 
14 |  | -        self.level = level  | 
15 | 11 |         self.left = None  | 
16 | 12 |         self.right = None  | 
17 | 13 | 
 
  | 
 | 14 | +    def __repr__(self):  | 
 | 15 | +        return '{}'.format(self.item)  | 
 | 16 | + | 
 | 17 | + | 
 | 18 | +    def _add(self, value):  | 
 | 19 | +        new_node = Node(value)  | 
18 | 20 | 
 
  | 
19 |  | -    def _addNextNode(self, value, level_here=1):  | 
20 |  | -        new_node = NodeBST(value, level_here)  | 
21 | 21 |         if not self.item:  | 
22 | 22 |             self.item = new_node  | 
 | 23 | + | 
23 | 24 |         else:  | 
24 | 25 |             if value > self.item:  | 
25 |  | -                self.right = self.right and self.right._addNextNode(value, level_here+1) or new_node  | 
 | 26 | +                self.right = self.right and self.right._add(value) or new_node  | 
26 | 27 |             elif value < self.item:  | 
27 |  | -                self.left = self.left and self.left._addNextNode(value, level_here+1) or new_node  | 
 | 28 | +                self.left = self.left and self.left._add(value) or new_node  | 
28 | 29 |             else:  | 
29 | 30 |                 print("BSTs do not support repeated items.")  | 
30 |  | -        return self # this is necessary!!!  | 
31 | 31 | 
 
  | 
 | 32 | +        return self # this is necessary!!!  | 
32 | 33 | 
 
  | 
33 | 34 | 
 
  | 
34 |  | -    def _searchForNode(self, value):  | 
 | 35 | +    def _search(self, value):  | 
35 | 36 |         if self.item == value:  | 
36 |  | -            return self  | 
 | 37 | +            return True # or self  | 
 | 38 | + | 
37 | 39 |         elif self.left and value < self.item:  | 
38 |  | -                return self.left._searchForNode(value)  | 
 | 40 | +                return self.left._search(value)  | 
 | 41 | + | 
39 | 42 |         elif self.right and value > self.item:  | 
40 |  | -                return self.right._searchForNode(value)  | 
 | 43 | +                return self.right._search(value)  | 
 | 44 | + | 
41 | 45 |         else:  | 
42 | 46 |             return False  | 
43 | 47 | 
 
  | 
44 | 48 | 
 
  | 
 | 49 | +    def _isLeaf(self):  | 
 | 50 | +        return not self.right and not self.left  | 
 | 51 | + | 
 | 52 | + | 
 | 53 | +    def _printPreorder(self):  | 
 | 54 | +        print self.item  | 
45 | 55 | 
 
  | 
46 |  | -class BinarySearchTree(BinaryTree):  | 
 | 56 | +        if self.left:  | 
 | 57 | +            return self.left._printPreorder()  | 
 | 58 | + | 
 | 59 | +        if self.right:  | 
 | 60 | +            return self.right._printPreorder()  | 
 | 61 | + | 
 | 62 | + | 
 | 63 | + | 
 | 64 | +class BST(object):  | 
47 | 65 | 
 
  | 
48 | 66 |     def __init__(self):  | 
49 | 67 |         self.root = None  | 
50 | 68 | 
 
  | 
51 |  | -    def addNode(self, value):  | 
 | 69 | +    def add(self, value):  | 
52 | 70 |         if not self.root:  | 
53 |  | -            self.root = NodeBST(value)  | 
 | 71 | +            self.root = Node(value)  | 
54 | 72 |         else:  | 
55 |  | -            self.root._addNextNode(value)  | 
 | 73 | +            self.root._add(value)  | 
 | 74 | + | 
 | 75 | +    def printPreorder(self):  | 
 | 76 | +        if self.root:  | 
 | 77 | +            self.root._printPreorder()  | 
56 | 78 | 
 
  | 
 | 79 | +    def search(self, value):  | 
 | 80 | +        if self.root:  | 
 | 81 | +            return self.root._search(value)  | 
57 | 82 | 
 
  | 
58 | 83 | 
 
  | 
59 | 84 | 
 
  | 
60 | 85 | if __name__ == '__main__':  | 
61 |  | -    bst = BinarySearchTree()  | 
 | 86 | + | 
 | 87 | +    bst = BST()  | 
62 | 88 |     print "Adding nodes 1 to 10 in the tree..."  | 
63 |  | -    for i in range(1, 10):  | 
64 |  | -        bst.addNode(i)  | 
65 |  | -    print "Is 8 a leaf? ", bst.isLeaf(8)  | 
66 |  | -    print "Whats the level of node 8? ", bst.getNodeLevel(8)  | 
67 |  | -    print "Is node 10 a root? ", bst.isRoot(10)  | 
68 |  | -    print "Is node 1 a root? ", bst.isRoot(1)  | 
69 |  | -    print "Whats the tree height? ", bst.getHeight()  | 
70 |  | -    print "Is this tree BST? ", bst.isBST()  | 
71 |  | -    print "Is this tree balanced? ", bst.isBalanced()  | 
 | 89 | +    for i in range(1, 11):  | 
 | 90 | +        bst.add(i)  | 
 | 91 | + | 
 | 92 | +    print  | 
 | 93 | +    print "Searching for nodes 16 and 6"  | 
 | 94 | +    print bst.search(16)  | 
 | 95 | +    print bst.search(6)  | 
 | 96 | + | 
 | 97 | +    print  | 
 | 98 | +    print "Printing preorder..."  | 
 | 99 | +    bst.printPreorder()  | 
 | 100 | + | 
 | 101 | + | 
72 | 102 | 
 
  | 
73 | 103 | 
 
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