Write a Function

You will be given one of the following problems to solve using and writing Python functions.

Given a list of words, return an array which indicates the frequency that each letter occurs. For example, in the list [”apple”, ”bob”], [ ’a’ -> 1, ’b’->2, ’e’->1, ’l’->1, ’o’->, ’p’->2] . The order of the array does not matter and a Frequency class will be provided.

Given a list of words, indicate whether the list constitutes a ”Word Lad- der.” A Word Ladder is a series of words where each succeeding word changes by only one letter. You may not assume that all words will be of the same length, and you may not assume the length of the list.

Given an integer greater than 2, X, return an array populated with all prime numbers up to and including X.

See

http://www.jiskha.com/display.cgi?id=1275046146

Most teachers will not go as far as the above response without seeing work from you. Do not expect someone here to write the functions for you from A to Z. We offer help, but do not do your homework.

Having said that, if you post your code with which you have difficulties debugging, teachers here will be glad to help you, both for the syntax and the logic.

To solve the given problems, you need to write Python functions. Here's an explanation of how to write each function:

1. Function to determine the frequency of each letter in a list of words:

To solve this problem, you can follow these steps:
- Create an empty dictionary to store the frequency of each letter.
- Iterate over each word in the given list.
- Iterate over each letter in the current word.
- For each letter, check if it's already a key in the dictionary. If it is, increment its value by 1. If it's not, add it as a new key with a value of 1.
- After iterating over all the words, convert the dictionary into a list of tuples using the `items()` method.
- Return the list of tuples.

Here's an example implementation:

```python
def calculate_letter_frequency(words):
frequency = {}
for word in words:
for letter in word:
frequency[letter] = frequency.get(letter, 0) + 1
return list(frequency.items())
```

2. Function to determine if a list of words forms a Word Ladder:

To solve this problem, you can follow these steps:
- Iterate over the given list of words starting from the second word.
- For each word, compare it with the previous word character by character.
- If there is more than one letter change between two consecutive words, return False indicating that it is not a Word Ladder.
- If you have iterated over all the words without returning False, return True indicating that it is a Word Ladder.

Here's an example implementation:

```python
def is_word_ladder(words):
for i in range(1, len(words)):
word1 = words[i - 1]
word2 = words[i]
differences = sum(a != b for a, b in zip(word1, word2))
if differences > 1:
return False
return True
```

3. Function to generate an array of prime numbers up to a given integer:

To solve this problem, you can follow these steps:
- Create an empty list to store the prime numbers.
- Iterate over each number from 2 to the given integer.
- For each number, check if it is divisible by any number from 2 to its square root (inclusive).
- If it is not divisible by any of those numbers, then it is a prime number, so add it to the list.
- Finally, return the list of prime numbers.

Here's an example implementation:

```python
import math

def generate_prime_numbers(x):
prime_numbers = []
for number in range(2, x + 1):
is_prime = True
for i in range(2, int(math.sqrt(number)) + 1):
if number % i == 0:
is_prime = False
break
if is_prime:
prime_numbers.append(number)
return prime_numbers
```

These functions should help you solve the given problems. Feel free to test them with some sample inputs to verify their correctness.