ashwin-op / b_and_bplus_tree Goto Github PK

In the file 'B-Tree.py'.
There are some code problem.
Details are as follows.
In function '_splitChild(self, x, i)',

t = self.t
        y = x.children[i]
        z = Node(y.leaf)
        x.children.insert(i + 1, z)
        x.keys.insert(i, y.keys[t - 1])
        z.keys = y.keys[t: (2 * t) - 1]
        y.keys = y.keys[0: t - 1]
        if not y.leaf:
            z.children = y.children[t: 2 * t]
            y.children = y.children[0: t - 1]

In my view, the correct version is:
z.keys = y.keys[t:(2t)-1]; y.keys = y.keys[0:t-2]
z.children=y.children[t:2t];y.children=y.children[0:t-1]

`def main():
B = BTree(2) ------ i changed

# Insert
customNo = 20   ------  i changed
for i in range(1,customNo+1):
    B.insert((i, randint(i, 5 * i)))
B.printTree(B.root)
print()

`

when i run，i get the following error：
`E:\workspace\PycharmProjects\B_and_Bplus_Tree\venv\Scripts\python.exe E:/workspace/PycharmProjects/B_and_Bplus_Tree/B-Tree.py
Level 0 --> 1: (8, 31)
Level 1 --> 1: (4, 10)
Level 2 --> 1: (2, 6)
Level 3 --> 1: (1, 4)
Level 1 --> 1: (12, 30)
Level 2 --> 1: (10, 19)
Level 3 --> 1: (9, 22)
Level 2 --> 3: (14, 32) (16, 42) (18, 25)
Level 3 --> 1: (13, 14)
Level 3 --> 1: (15, 27)
Level 3 --> 1: (17, 58)
Level 3 --> 2: (19, 76) (20, 71)

Key 12 deleted!
Traceback (most recent call last):
File "E:/workspace/PycharmProjects/B_and_Bplus_Tree/B-Tree.py", line 313, in
main()
File "E:/workspace/PycharmProjects/B_and_Bplus_Tree/B-Tree.py", line 298, in main
B.delete(B.root, (toDelete,))
File "E:/workspace/PycharmProjects/B_and_Bplus_Tree/B-Tree.py", line 156, in delete
self.delete(x.children[i], k)
IndexError: list index out of range

Process finished with exit code 1
`

There is a typo in the realization of B-tree.
It's necessary to change in file B-Tree.py in function _deletePredecessor line #193 from

return x.pop()

to

return x.keys.pop()

Since argument x is not a list of keys, it is an object-node that contains a list of keys.