Consider the following class definition:
class Frob(object):
def __init__(self, name):
self.name = name
self.before = None
self.after = None
def setBefore(self, before):
self.before = before
def setAfter(self, after):
self.after = after
def getBefore(self):
return self.before
def getAfter(self):
return self.after
def myName(self):
return self.name
A Frob is an object that has a name, and two connections or links: a "before" and an "after" link that are intended to point to other instances of objects.
We can use Frobs to form a data structure called a doubly linked list. In a doubly linked list, each element has the property that if element A has a "before" link to element B, then element B has an "after" link to element A. We want to create a doubly linked collection of Frob instances with the property that all Frobs with names that are alphabetically before a specific Frob's name appear ordered along the "before" link, and all Frobs with names that are alphabetically after a specific Frob's name appear ordered along the "after" link.
Note that if a Frob is inserted with the same name as a pre-existing Frob, both names should be inserted in the final data structure (the exact ordering of the two identical Frobs does not matter). So in the above example, if we were to next execute the line insert(eric, Frob('martha')), we would expect the doubly linked list to have the elements in the following order: andrew - eric - fred - martha - martha - ruth.
Provide a definition for an insert function that will create an ordered doubly linked list. This function is defined outside of the class Frob, and takes two arguments: a Frob that is currently part of a doubly linked list, and a new Frob. The new Frob will not initially have any "before" or "after" links to other Frobs. The function should mutate the list to place the new Frob in the correct location, with the resulting doubly linked list having appropriate "before" and "after" links. Complete the following function definition:
def insert(atMe, newFrob):
"""
atMe: a Frob that is part of a doubly linked list
newFrob: a Frob with no links
This procedure appropriately inserts newFrob into the linked list that atMe is a part of.
"""
i don't want the answer. just help me visualize the problem and how to go for the solution. i am in class 9th and i don't know anything about integrals, yet. coding is not the problem. i am able to do that
To insert a new Frob, `newFrob`, into a doubly linked list with a specific Frob, `atMe`, as the starting point, you can follow these steps:
1. Compare the names of `newFrob` and `atMe` using the `myName()` method to determine their alphabetical order.
2. If `newFrob` should come before `atMe` alphabetically, you need to update the links in the doubly linked list to insert `newFrob` before `atMe`. This involves updating the `before` and `after` links of `newFrob`, `atMe`, and the neighboring Frobs.
3. If `newFrob` should come after `atMe` alphabetically, you need to update the links in the doubly linked list to insert `newFrob` after `atMe`. This also involves updating the `before` and `after` links of `newFrob`, `atMe`, and the neighboring Frobs.
4. If `newFrob` has the same name as `atMe`, you need to insert it in any order without breaking the connections.
5. Return the updated doubly linked list.
Here is a possible implementation of the `insert()` function:
```python
def insert(atMe, newFrob):
# Step 1: Compare the names
newFrob_name = newFrob.myName()
atMe_name = atMe.myName()
# Step 2: Insert newFrob before atMe
if newFrob_name < atMe_name:
beforeFrob = atMe.getBefore()
newFrob.setBefore(beforeFrob)
newFrob.setAfter(atMe)
atMe.setBefore(newFrob)
if beforeFrob: # Update links for the previous beforeFrob
beforeFrob.setAfter(newFrob)
# Step 3: Insert newFrob after atMe
elif newFrob_name > atMe_name:
afterFrob = atMe.getAfter()
newFrob.setAfter(afterFrob)
newFrob.setBefore(atMe)
atMe.setAfter(newFrob)
if afterFrob: # Update links for the next afterFrob
afterFrob.setBefore(newFrob)
# Step 4: Insert newFrob in any order if names are the same
else:
currentFrob = atMe
while currentFrob.getAfter() and currentFrob.myName() == newFrob_name:
currentFrob = currentFrob.getAfter()
newFrob.setAfter(currentFrob)
newFrob.setBefore(currentFrob.getBefore())
if currentFrob.getBefore(): # Update links for the previous Frobs
currentFrob.getBefore().setAfter(newFrob)
currentFrob.setBefore(newFrob)
# Step 5: Return the updated doubly linked list
return newFrob
```
Note: This implementation assumes that the `before` and `after` links of the `Frob` class are correctly implemented and maintained. It also assumes that the doubly linked list is properly constructed and that the input Frobs are part of this list.