|
| 1 | +''' |
| 2 | +A AVL tree |
| 3 | +''' |
| 4 | + |
| 5 | + |
| 6 | +class Node: |
| 7 | + |
| 8 | + def __init__(self, label): |
| 9 | + self.label = label |
| 10 | + self.left = None |
| 11 | + self.rigt = None |
| 12 | + self.parent = None |
| 13 | + self.height = 0 |
| 14 | + |
| 15 | + def getLabel(self): |
| 16 | + return self.label |
| 17 | + |
| 18 | + def setLabel(self, label): |
| 19 | + self.label = label |
| 20 | + |
| 21 | + def getLeft(self): |
| 22 | + return self.left |
| 23 | + |
| 24 | + def setLeft(self, left): |
| 25 | + self.left = left |
| 26 | + |
| 27 | + def getRight(self): |
| 28 | + return self.rigt |
| 29 | + |
| 30 | + def setRight(self, right): |
| 31 | + self.rigt = right |
| 32 | + |
| 33 | + def getParent(self): |
| 34 | + return self.parent |
| 35 | + |
| 36 | + def setParent(self, parent): |
| 37 | + self.parent = parent |
| 38 | + |
| 39 | + def setHeight(self, height): |
| 40 | + self.height = height |
| 41 | + |
| 42 | + def getHeight(self, height): |
| 43 | + return self.height |
| 44 | + |
| 45 | + |
| 46 | +class AVL: |
| 47 | + |
| 48 | + def __init__(self): |
| 49 | + self.root = None |
| 50 | + self.size = 0 |
| 51 | + |
| 52 | + def insert(self, value): |
| 53 | + node = Node(value) |
| 54 | + if self.root is None: |
| 55 | + self.root = node |
| 56 | + self.size = 1 |
| 57 | + else: |
| 58 | + # Same as Binary Tree |
| 59 | + dad_node = None |
| 60 | + curr_node = self.root |
| 61 | + |
| 62 | + while True: |
| 63 | + if curr_node is not None: |
| 64 | + |
| 65 | + dad_node = curr_node |
| 66 | + |
| 67 | + if node.getLabel() < curr_node.getLabel(): |
| 68 | + curr_node = curr_node.getLeft() |
| 69 | + else: |
| 70 | + curr_node = curr_node.getRight() |
| 71 | + else: |
| 72 | + if node.getLabel() < dad_node.getLabel(): |
| 73 | + dad_node.setLeft(node) |
| 74 | + dad_node.setHeight(dad_node.getHeight() + 1) |
| 75 | + |
| 76 | + if (dad_node.getRight().getHeight() - |
| 77 | + dad_node.getLeft.getHeight() > 1): |
| 78 | + self.rebalance(dad_node) |
| 79 | + |
| 80 | + else: |
| 81 | + dad_node.setRight(node) |
| 82 | + dad_node.setHeight(dad_node.getHeight() + 1) |
| 83 | + |
| 84 | + if (dad_node.getRight().getHeight() - |
| 85 | + dad_node.getLeft.getHeight() > 1): |
| 86 | + self.rebalance(dad_node) |
| 87 | + break |
| 88 | + |
| 89 | + def rebalance(self, node): |
| 90 | + if (node.getRight().getHeight() - |
| 91 | + node.getLeft.getHeight() > 1): |
| 92 | + if (node.getRight().getHeight() > |
| 93 | + node.getLeft.getHeight()): |
| 94 | + pass |
| 95 | + else: |
| 96 | + pass |
| 97 | + pass |
| 98 | + elif (node.getRight().getHeight() - |
| 99 | + node.getLeft.getHeight() > 2): |
| 100 | + if (node.getRight().getHeight() > |
| 101 | + node.getLeft.getHeight()): |
| 102 | + pass |
| 103 | + else: |
| 104 | + pass |
| 105 | + pass |
| 106 | + pass |
| 107 | + |
| 108 | + def rotate_left(self, node): |
| 109 | + # TODO: is this pythonic enought? |
| 110 | + aux = node.getLabel() |
| 111 | + node = aux.getRight() |
| 112 | + node.setHeight(node.getHeight() - 1) |
| 113 | + node.setLeft(Node(aux)) |
| 114 | + node.getLeft().setHeight(node.getHeight() + 1) |
| 115 | + node.getRight().setHeight(node.getRight().getHeight() - 1) |
| 116 | + |
| 117 | + def rotate_right(self, node): |
| 118 | + aux = node.getLabel() |
| 119 | + node = aux.getLeft() |
| 120 | + node.setHeight(node.getHeight() - 1) |
| 121 | + node.setRight(Node(aux)) |
| 122 | + node.getLeft().setHeight(node.getHeight() + 1) |
| 123 | + node.getLeft().setHeight(node.getLeft().getHeight() - 1) |
| 124 | + |
| 125 | + def double_rotate_left(self, node): |
| 126 | + self.rotate_right(node.getRight().getRight()) |
| 127 | + self.rotate_left(node) |
| 128 | + |
| 129 | + def double_rotate_right(self, node): |
| 130 | + self.rotate_left(node.getLeft().getLeft()) |
| 131 | + self.rotate_right(node) |
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