CS Cloud Computing Assignment 1 Solution

Solve the following problems in Python 3.6+ .

In addition to making sure that your code gives the correct solution, each solution must meet the following conditions.

        1. Your function parameters must be [type hinted](https://docs.python.org/3.6/library/typing.html]). These need not be perfect, but should be generally correctly describe your input and output.
    2. Your functions must have a doc-string describing what the function does. Keep is succinct and concise.
    3. Use a auto-formatter such as

[black](https://pypi.org/project/black/) or

[autopep8](https://pypi.org/project/autopep8/).

4. Write atleast 2 simple

[doctests](https://docs.python.org/3.6/library/doctest.html) per solution to verify that your code is working correctly. 5. Use descriptive variable names.

Here is an example of what your code should look like.

For example

```python

from typing import List

def average(num_list: List[int]) -> float:

"""Finds the average of a list of numbers.

doctests:

    • average([1,2,3,4,5])

3.0

    • average([0])

0.0

"""

list_sum = sum(num_list)

list_size = len(num_list)

avg = list_sum/list_size

return avg

if __name__ == "__main__":

import doctest

doctest.testmod()

```

## Problem 1
Write a function to break down a string into a list of characters.

```

Input: "abc"

Output: ['a','b','c']

```

## Problem 2

Write a function to reverse output of the problem 1 back into a string ```

Input: ['a','b','c']

Output: "abc"

```

## Problem 3

Write a function generate a list of n random numbers.

Use the inbuilt `random` module.

```

Input: 5

Output: [5,2,3,1,5]

```

## Problem 4

Write a function a sort a given list of numbers in descending order.

```

Input: [1,2,3,4,5]

Output: [5,4,3,2,1]

```

## Problem 5

Write a function to get frequency of each numbers in a list of numbers. Use a python `dict` to solve this.

```

Input: [1,1,3,2,3,2,3,2,2]

Output: {1: 2, 3: 3, 2: 4}

```

## Problem 6

Write a function to get all the unique elements from given list. Your solution must use `set` to solve this.

```

Input: [1,1,3,2,3,2,3,2,2]

Output: {1,2,3}

```

## Problem 7

Write a function to get the first repeating element from list. Your solution must use `set` to solve this.

```

Input: [1,2,3,4,5,1,2]

Output: 1

```

## Problem 8

Write a function that takes an integer n and output a `dict` containing keys from 0,2 ... to n and each key is mapped to a list containing the square and cube of the number.

```

Input: 3

Output:

{

0:[0,0],

1:[1,1],

2:[4,8],

3:[9,27]

}

```

## Problem 9

Given two lists of equal size, write a function to create tuples of each consecutive element having same index. Use `zip` in some capacity to solve this.

```

Input: [1,2,3,4], ['a','b','c','d']

Output: [(1,'a'), (2,'b'), (3,'c'), (4,'d')]

```

## Problem 10

Write a function that uses list comprehension to generate the squares of 0 to n.

```

Input : 5

Output : [0, 1, 4, 9, 16, 25]

```

## Problem 11

Write a function that uses dictionary comprehension to generate a mapping from (0 to n) to their squares.

```

Input : 5

Output : {0:0, 1:1, 2:4, 3:9, 4:16, 5:25}

```

## Problem 12.

Write a `class` such that :

        1. The initializer takes an arbitrary list of atomic values as input and saves it in a instance variable.
    2. Has a method called `apply` which has the following functionality: 1. Accepts a function as a parameter. You can use a lambda function.

            2. Applies the function to saved list and return the output. The instance variable must not be modified.
            3. If it fails `raise` an `Exception` with a custom error message. You can use `try` and `except` here.

```python
def sq(x):

return x**2

c1 = MyClass([1,2,3,4])

print(c1.apply(lambda x:x**2))

[1,4,9,16]

c2 = MyClass(['a','b','c'])

c2.apply(sq)

----------------------------------------------------------------------- ----

TypeError Traceback (most recent call last)

....

....

Exception: Custom Error

```

## Problem 13

Write a function takes as input a list of words and upper-cases each word. Use `functools.map` in some capacity to solve this.

```

Input : ['aa','bb','cd','e']

Output : ['AA', 'BB', 'CD', 'E']

```

## Problem 14:

Write a function to find the product of all the numbers in a list using `functools.reduce` in some capacity.

```

Input : [1,2,3,4,5]

Output : 120

```