gradedassignment

 1)

Explanation:

1. Initialization of L:

   css
   L = [[0, 210, 78], [1, 198, 91], [2, 188, 77], [3, 173, 78], [4, 240, 89]]
   

   L is a list of lists, where each inner list now has three elements instead of two.

2. Initialization of mList:

   css
   mList = []
   

   mList is initialized as an empty list, which will store values extracted from L in the loop.

3. Looping through each element in L:

   csharp
   foreach element in L{
       mList = mList ++ [last(init(element))]
   }
   

   Let's break down what this line is doing:

   • element represents each inner list in L (e.g., [0, 210, 78], [1, 198, 91], etc.).
   • init(element) removes the last item of element. For instance, if element is [0, 210, 78], then init(element) is [0, 210].
   • last(init(element)) takes the last item of this modified list (after removing the last item of the original element). For [0, 210], the last item is 210.

4. Appending to mList:

   • mList = mList ++ [last(init(element))] appends the result of last(init(element)) to mList.

Step-by-Step Execution of the Loop

Let’s go through each element in L and apply last(init(element)):

1. For the first element [0, 210, 78]:

   • init([0, 210, 78]) = [0, 210]
   • last([0, 210]) = 210
   • mList becomes [210]

2. For the second element [1, 198, 91]:

   • init([1, 198, 91]) = [1, 198]
   • last([1, 198]) = 198
   • mList becomes [210, 198]

3. For the third element [2, 188, 77]:

   • init([2, 188, 77]) = [2, 188]
   • last([2, 188]) = 188
   • mList becomes [210, 198, 188]

4. For the fourth element [3, 173, 78]:

   • init([3, 173, 78]) = [3, 173]
   • last([3, 173]) = 173
   • mList becomes [210, 198, 188, 173]

5. For the fifth element [4, 240, 89]:

   • init([4, 240, 89]) = [4, 240]
   • last([4, 240]) = 240
   • mList becomes [210, 198, 188, 173, 240]

Final Value of mList

After processing all elements in L, the final value of mList is:

css
mList = [210, 198, 188, 173, 240]

Answer:

The final value of mList is:

csharp
[210, 198, 188, 173, 240]

Question:-2

The terms init(element) and last(element) are not Python built-in functions. These terms are used here as pseudocode concepts to describe specific operations on lists or arrays. Here’s a breakdown of these concepts and their Python equivalents, along with other related list manipulation methods that are useful to know.
List Manipulation Concepts in Pseudocode
init(element):
Description: init(element) refers to taking all items of a list except the last item.
Example: If element = [0, 210, 78], then init(element) would return [0, 210].
Python Equivalent: This can be achieved using slicing:
python
element[:-1]
Here, element[:-1] returns all elements except the last one.
last(element):
Description: last(element) refers to taking the last item of a list.
Example: If element = [0, 210, 78], then last(element) would return 78.
Python Equivalent: This can also be achieved using indexing:
python
element[-1]
Here, element[-1] accesses the last element in the list.
Related List Manipulation Techniques in Python
Python provides several methods and functions for list manipulation. Here are some key techniques:
first(element) (Pseudocode Concept):
Description: first(element) refers to taking the first item of a list.
Example: If element = [0, 210, 78], then first(element) would return 0.
Python Equivalent:
python
element[0]
Slicing a List:
Description: Slicing allows you to access a subset of elements in a list. It’s commonly used to get specific portions of a list.
Syntax: list[start:stop:step]
Examples:
All elements except the first: element[1:]
All elements except the last: element[:-1]
A specific range: element[1:3] (selects elements at indices 1 and 2)
Removing Elements:
Description: Python provides methods to remove elements from a list.
Methods:
Remove by value: list.remove(value) removes the first occurrence of value.
Remove by index: del list[index] or list.pop(index) removes the element at a specific index.
Example:
python
element = [0, 210, 78]
element.remove(210)  # element becomes [0, 78]
del element[1]       # element becomes [0]
Adding Elements:
Description: You can add elements to a list using append, extend, and concatenation (+).
Methods:
Append a single item: list.append(item)
Extend with multiple items: list.extend([item1, item2])
Concatenate lists: list1 + list2
Example:
python
element = [0, 210]
element.append(78)           # element becomes [0, 210, 78]
element.extend([100, 200])   # element becomes [0, 210, 78, 100, 200]
Reversing a List:
Description: You can reverse the order of elements in a list.
Methods:
Reverse in place: list.reverse()
Return reversed list: reversed_list = list[::-1]
Example:
python
element = [0, 210, 78]
element.reverse()            # element becomes [78, 210, 0]
Finding the Length of a List:
Description: The len() function gives the total number of elements in a list.
Example:
python
element = [0, 210, 78]
len(element)  # Returns 3
Sorting a List:
Description: You can sort lists in ascending or descending order.
Methods:
Sort in place: list.sort() (for ascending) or list.sort(reverse=True) (for descending)
Return sorted list: sorted_list = sorted(list)
Example:
python
element = [210, 0, 78]
element.sort()              # element becomes [0, 78, 210]
Finding Maximum and Minimum:
Description: Use max() and min() to get the maximum and minimum values in a list.
Examples:
python
element = [0, 210, 78]
max(element)  # Returns 210
min(element)  # Returns 0
Summary of Pseudocode Terms and Python Equivalents
Pseudocode Concept
Description
Python Equivalent
init(element)
All elements except the last
element[:-1]
last(element)
The last element
element[-1]
first(element)
The first element
element[0]
Append Element(s)
Add items to the list
element.append() or +
Remove Element(s)
Remove by value or index
element.remove() or del
Slice List
Access specific portions
element[start:stop:step]
Length
Count of elements
len(element)
Reverse
Reverse the order
element.reverse()
Sort
Sort in ascending/descending order
element.sort() or sorted()
Max/Min
Largest or smallest element
max(element), min(element)
These operations allow for versatile manipulation of lists in Python.




question 3) 
In the pseudocode provided, rest(newList) is used to refer to a function or operation that removes the first element of a list and returns the remaining elements. It essentially "takes the rest" of the list after the first item.
Let’s go through how rest(newList) works with examples to clarify its behavior.
Understanding rest(newList)
When you apply rest to a list, it removes the first element and returns the remaining list. For instance:
If newList = [1, 2, 3, 4], then rest(newList) = [2, 3, 4].
If newList = [a, b, c], then rest(newList) = [b, c].
The rest function is common in some functional programming languages like Lisp or Scheme, and it simply returns the "tail" of a list, leaving out the first element. Python has similar slicing functionality to achieve this effect.
Using rest in someList
In the pseudocode’s someList function, rest is used twice in each iteration of the while loop. Here’s how it plays out:
newList = rest(rest(newList)) effectively removes the first two elements of newList each time the loop runs.
Example Execution of someList
Let’s go through an example of how someList works step-by-step.
Suppose X = [1, 2, 3, 4, 5, 6].
plaintext
Procedure someList(X)
    outlist = [], newList = X
    while(length(newList) > 0){
        outlist = outlist ++ [first(newList)]
        newList = rest(rest(newList))
    }
    return(outlist)
End someList
Initialization:
outlist = []
newList = [1, 2, 3, 4, 5, 6]
First Iteration:
first(newList) = 1, so outlist = [1]
Update newList = rest(rest(newList)), which means removing the first two elements:
newList = [3, 4, 5, 6]
Second Iteration:
first(newList) = 3, so outlist = [1, 3]
Update newList = rest(rest(newList)), removing the first two elements again:
newList = [5, 6]
Third Iteration:
first(newList) = 5, so outlist = [1, 3, 5]
Update newList = rest(rest(newList)), removing the first two elements:
newList = []
End of Loop:
newList is now empty, so the loop terminates.
The function returns outlist = [1, 3, 5].
Summary
The someList function, using rest(rest(newList)), effectively skips every other element in the original list X, starting with the first element.
Key Takeaway:
rest(newList) removes the first element of a list.
rest(rest(newList)) removes the first two elements of a list.


If someList is applied to a list of the first 50 positive integers, N = [1, 2, 3, ..., 49, 50], the function will produce a list of all odd numbers from 1 to 49 as outlist. Let’s walk through this in detail.
Step-by-Step Execution of someList on N = [1, 2, 3, ..., 49, 50]
Initialization:
outlist = []
newList = N = [1, 2, 3, ..., 49, 50]
First Iteration:
first(newList) = 1, so we add 1 to outlist.
outlist = [1]
Update newList = rest(rest(newList)), which removes the first two elements, so:
newList = [3, 4, 5, ..., 49, 50]
Second Iteration:
first(newList) = 3, so we add 3 to outlist.
outlist = [1, 3]
Update newList = rest(rest(newList)), removing the first two elements:
newList = [5, 6, 7, ..., 49, 50]
Subsequent Iterations:
This process continues, with each iteration adding the next odd number to outlist and skipping the next even number by removing two elements at a time from newList.
Final Iteration:
When first(newList) = 49, we add 49 to outlist.
outlist = [1, 3, 5, ..., 47, 49]
Now, newList = [50], so rest(rest(newList)) makes newList empty, and the loop terminates.
Result
At the end of this process, outlist will contain all the odd numbers from 1 to 49:
$$\text{outlist} = [1, 3, 5, 7, 9, \dots, 47, 49]$$
This is because someList with rest(rest(newList)) effectively skips every other element, resulting in the sequence of odd numbers from the original list.
What Happens in the Pseudocode with A and B
Now that someList on N gives us all the odd numbers between 1 and 49 for A, let’s look at B and what happens in the main code:
Generating List A:
A = someList(N) = [1, 3, 5, ..., 49] (all odd numbers between 1 and 49).
Generating List B:
B = someList(rest(N)). Since rest(N) starts from the second element, rest(N) = [2, 3, 4, ..., 49, 50].
Applying someList to rest(N) gives every other element starting with the second element, resulting in:
$$B = [2, 4, 6, ..., 50]$$
This gives B as all even numbers from 2 to 50.
Counting Common Elements:
In the main pseudocode, we check each element of A against each element of B.
Since A contains only odd numbers and B contains only even numbers, there are no common elements between A and B.
Therefore, the count variable remains 0.
Final Value of count
Given that there are no common elements between A and B:
$$\text{count} = 0$$
Summary
A will be [1, 3, 5, ..., 49] (all odd numbers between 1 and 49).
B will be [2, 4, 6, ..., 50] (all even numbers between 2 and 50).
count will be 0 since there are no common elements between A and B.