fix: correct treap split() comparison to match docstring behavior (#14762)

* fix: correct treap split() to match docstring for equal values (#7854)

The split() function in treap.py uses `<` comparison but the docstring states that the right subtree should contain values "greater or equal" to the split value. This fix changes `elif value < root.value:` to `elif value <= root.value:` so that equal values go to the right subtree as documented.

Fixes #7854

* Fix typo in Treap node docstringfix: remove accidental typo in Node class docstring

* Fix erase logic in treap.py

Adjust split logic to include the value in the right subtree.

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Co-authored-by: Christian Clauss <cclauss@me.com>

Author: maitriupadhyay03-cell

data_structures/binary_tree/treap.py

@@ -41,7 +41,7 @@ def split(root: Node | None, value: int) -> tuple[Node | None, Node | None]:
     """
     if root is None or root.value is None:  # None tree is split into 2 Nones
         return None, None
-    elif value < root.value:
+    elif value <= root.value:
         """
         Right tree's root will be current node.
         Now we split(with the same value) current node's left son
@@ -101,8 +101,8 @@ def erase(root: Node | None, value: int) -> Node | None:
     Split all nodes with values greater into right.
     Merge left, right
     """
-    left, right = split(root, value - 1)
-    _, right = split(right, value)
+    left, right = split(root, value)
+    _, right = split(right, value + 1)
     return merge(left, right)