|
| 1 | +import os |
| 2 | + |
| 3 | + |
| 4 | +class _Node: |
| 5 | + ''' |
| 6 | + Initialises node with the passed arguments, None if no arguments are passed. |
| 7 | + ''' |
| 8 | + __slots__ = '_element', '_left', '_right' |
| 9 | + |
| 10 | + def __init__(self, element, left=None, right=None): |
| 11 | + self._element = element |
| 12 | + self._left = left |
| 13 | + self._right = right |
| 14 | + |
| 15 | + |
| 16 | +class BinaryTree: |
| 17 | + def __init__(self): |
| 18 | + ''' |
| 19 | + Initialises Root node to None. |
| 20 | + ''' |
| 21 | + self._root = None |
| 22 | + |
| 23 | + def createTree(self, node): |
| 24 | + ''' |
| 25 | + Recursively adds node to the tree using Postorder traversing pattern. |
| 26 | + That means, it will first ask to add all the left childs of root |
| 27 | + and then right child of the most recently added node. |
| 28 | + ''' |
| 29 | + # os.system('cls') |
| 30 | + position = input( |
| 31 | + f"Add node on the Left of {node._element} ? [y/n]: ") |
| 32 | + if position == 'y': |
| 33 | + nodeData = int(input("Enter data for node: ")) |
| 34 | + curr = _Node(nodeData) |
| 35 | + node._left = curr |
| 36 | + self.createTree(curr) |
| 37 | + |
| 38 | + # os.system('cls') |
| 39 | + position = input( |
| 40 | + f"Add node on the Right of {node._element} ? [y/n]: ") |
| 41 | + if position == 'y': |
| 42 | + nodeData = int(input("Enter data for node: ")) |
| 43 | + curr = _Node(nodeData) |
| 44 | + node._right = curr |
| 45 | + self.createTree(curr) |
| 46 | + |
| 47 | + def createRoot(self): |
| 48 | + ''' |
| 49 | + Function to create Root node. |
| 50 | + ''' |
| 51 | + rootData = int(input("Enter data for Root: ")) |
| 52 | + self._root = _Node(rootData) |
| 53 | + self.createTree(self._root) |
| 54 | + |
| 55 | + def inorder(self, troot): |
| 56 | + ''' |
| 57 | + Function for Inorder Traversal. |
| 58 | + ''' |
| 59 | + if troot: |
| 60 | + self.inorder(troot._left) |
| 61 | + print(troot._element, end=" ") |
| 62 | + self.inorder(troot._right) |
| 63 | + |
| 64 | + def preorder(self, troot): |
| 65 | + ''' |
| 66 | + Function for Preorder Traversal. |
| 67 | + ''' |
| 68 | + if troot: |
| 69 | + print(troot._element, end=" ") |
| 70 | + self.preorder(troot._left) |
| 71 | + self.preorder(troot._right) |
| 72 | + |
| 73 | + def postorder(self, troot): |
| 74 | + ''' |
| 75 | + Function for Postorder Traversal. |
| 76 | + ''' |
| 77 | + if troot: |
| 78 | + self.postorder(troot._left) |
| 79 | + self.postorder(troot._right) |
| 80 | + print(troot._element, end=" ") |
| 81 | + |
| 82 | +############################################################################### |
| 83 | + |
| 84 | + |
| 85 | +def options(): |
| 86 | + ''' |
| 87 | + Prints Menu for operations |
| 88 | + ''' |
| 89 | + options_list = ['Create Tree', 'Inorder', 'Preorder', |
| 90 | + 'Postorder', 'Exit'] |
| 91 | + |
| 92 | + print("\nMENU") |
| 93 | + for i, option in enumerate(options_list): |
| 94 | + print(f'{i + 1}. {option}') |
| 95 | + |
| 96 | + choice = int(input("Enter choice: ")) |
| 97 | + return choice |
| 98 | + |
| 99 | + |
| 100 | +def switch_case(choice): |
| 101 | + ''' |
| 102 | + Switch Case for operations |
| 103 | + ''' |
| 104 | + # os.system('cls') |
| 105 | + if choice == 1: |
| 106 | + bt.createRoot() |
| 107 | + |
| 108 | + elif choice == 2: |
| 109 | + print("Inorder Traversal:") |
| 110 | + bt.inorder(bt._root) |
| 111 | + |
| 112 | + elif choice == 3: |
| 113 | + print("Preorder Traversal:") |
| 114 | + bt.preorder(bt._root) |
| 115 | + |
| 116 | + elif choice == 4: |
| 117 | + print("Postorder Traversal:") |
| 118 | + bt.postorder(bt._root) |
| 119 | + |
| 120 | + elif choice == 5: |
| 121 | + import sys |
| 122 | + sys.exit() |
| 123 | + |
| 124 | +############################################################################### |
| 125 | + |
| 126 | + |
| 127 | +bt = BinaryTree() |
| 128 | +while True: |
| 129 | + choice = options() |
| 130 | + switch_case(choice) |
| 131 | + |
| 132 | +''' |
| 133 | +MENU |
| 134 | +1. Create Tree |
| 135 | +2. Inorder |
| 136 | +3. Preorder |
| 137 | +4. Postorder |
| 138 | +5. Exit |
| 139 | +Enter choice: 1 |
| 140 | +Enter data for Root: 10 |
| 141 | +Add node on the Left of 10 ? [y/n]: y |
| 142 | +Enter data for node: 20 |
| 143 | +Add node on the Left of 20 ? [y/n]: n |
| 144 | +Add node on the Right of 20 ? [y/n]: n |
| 145 | +Add node on the Right of 10 ? [y/n]: y |
| 146 | +Enter data for node: 30 |
| 147 | +Add node on the Left of 30 ? [y/n]: n |
| 148 | +Add node on the Right of 30 ? [y/n]: n |
| 149 | + |
| 150 | +MENU |
| 151 | +1. Create Tree |
| 152 | +2. Inorder |
| 153 | +3. Preorder |
| 154 | +4. Postorder |
| 155 | +5. Exit |
| 156 | +Enter choice: 2 |
| 157 | +Inorder Traversal: |
| 158 | +20 10 30 |
| 159 | +MENU |
| 160 | +1. Create Tree |
| 161 | +2. Inorder |
| 162 | +3. Preorder |
| 163 | +4. Postorder |
| 164 | +5. Exit |
| 165 | +Enter choice: 3 |
| 166 | +Preorder Traversal: |
| 167 | +10 20 30 |
| 168 | +MENU |
| 169 | +1. Create Tree |
| 170 | +2. Inorder |
| 171 | +3. Preorder |
| 172 | +4. Postorder |
| 173 | +5. Exit |
| 174 | +Enter choice: 4 |
| 175 | +Postorder Traversal: |
| 176 | +20 30 10 |
| 177 | +''' |
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