Last week, a typical nested linked list is constructed such that self.head points to a value and self.rest points to the subsequent linked linked. Th key thing is that each linked list end with an empty linked list.
This week,we investigates a different way of representing a linked list with the help of the creation of a new class node. In my understanding, node works in a similar way as last week's linked list. And the whole node structure is stored in one of linked list's attribute.
Similarly, binary tree can be repressed suing BTNode. The idea seems to be to transfer a recursive structure to a different class, though I don't get why we have to do so. In the printing method, in order to demonstrate a visually appealing graph, a contra in order traversal is used here to print the right side first. We further apply BTNode to BST(binary search tree). As a result, binary search tree is no longer a true structure, but more likely a BTNode recursive structure. But regarding the _insert function, why do we have to create a return_node and let it equal to node? What's wrong with directly modify node
Question:
1.I find in lab that COPY in linked list can be tricky, because each linked list occupies a unique id address. Changing its value, however, could cause aliasing(if that's the correct word). So I am wondering should we use deep copy instead of the shallow copy method?
Here is and illuminating answer i copy down from piazza: "Shallow copy - your first code chunk has 3 assignments and 1 shallow copy. copy.copy(x) creates a new object y, with id(y) ≠ id(x), such that for every attribute s of x, id(x.s) = id(y.x). So y is a distinct copy of x in basically the most superficial (shallow) way possible."
2. I am having trouble understanding the code for reversing a linked list.
3. when i can an object of a class in python shell, does it return __str__ or __repr__ of the object
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