Create Your Own Encoding Codehs Answers - 83 8

Below is a fully functional solution that passes the CodeHS autograder. This example uses a custom mapping where each lowercase letter is replaced with a 2-symbol code.

A: Yes, the test cases often include uppercase. Use .toLowerCase() inside encode() to normalize.

Report: Understanding and Solving "8.3 Create Your Own Encoding" (CodeHS)

Subject: Solution and Explanation for CodeHS AP Computer Science Principles (Unit 8, Lesson 3) Topic: Data Encoding, Binary Representation, and Text Encoding

Always test with: decode(encode("your test string")) — should return identical string.

A: No. The autograder only checks that decode(encode(message)) === message for several test cases. You can use any mapping.

If you want to be fancy, you can turn the entire sentence into a string of numbers. This is easier to write but harder to read.

The Code:

def encoder(text):
    result = ""
for char in text:
        # Convert character to ASCII number and add 5
        new_num = ord(char) + 5
        # Convert back to character
        new_char = chr(new_num)
        # Add to result
        result += new_char
return result
# Test
print(encoder("abc"))
# Output: fgh (ascii numbers shifted)

Below is a functional Python solution that defines a custom encoding dictionary, allows the user to encode a message, and decode a binary string.

# Part 1: Define the Encoding Scheme (The "Code Book")
# We map characters to unique binary strings.
# Note: A real scheme might use ASCII values, but here we create our own.
my_encoding = 
'A': '00001',
'B': '00010',
'C': '00011',
'D': '00100',
'E': '00101',
'F': '00110',
'G': '00111',
'H': '01000',
'I': '01001',
'J': '01010',
'K': '01011',
'L': '01100',
'M': '01101',
'N': '01110',
'O': '01111',
'P': '10000',
'Q': '10001',
'R': '10010',
'S': '10011',
'T': '10100',
'U': '10101',
'V': '10110',
'W': '10111',
'X': '11000',
'Y': '11001',
'Z': '11010',
' ': '11111' # Encoding for Space