Encode

"TIP102 Unit 1 Session 1 Advanced (Click for link to problem statements)

Problem Highlights

• 💡 Difficulty: Easy
• ⏰ Time to complete: 10 mins
• 🛠️ Topics: Arrays, String Manipulation, Indexing

U-nderstand

Understand what the interviewer is asking for by using test cases and questions about the problem.

• Established a set (2-3) of test cases to verify their own solution later.
• Established a set (1-2) of edge cases to verify their solution handles complexities.
• Have fully understood the problem and have no clarifying questions.
• Have you verified any Time/Space Constraints for this problem?

• The function shuffle() should take a string message and an integer array indices and return a shuffled version of the string where each character in message is moved to the position specified by indices.

HAPPY CASE
Input: message = ""evil"", indices = [3,1,2,0]
Expected Output: ""lvie""

Input: message = ""findme"", indices = [0,1,2,3,4,5]
Expected Output: ""findme""

EDGE CASE
Input: message = ""a"", indices = [0]
Expected Output: ""a""

P-lan

Plan the solution with appropriate visualizations and pseudocode.

General Idea: Initialize an empty list of the same length as the message, then place each character in the new list at the index specified by indices. Finally, join the list into a string.

1. Initialize a list `shuffled_message` with empty strings of the same length as `message`.
2. Iterate through each character in `message` using its index `i`.
    a. Place the character `message[i]` at the position `indices[i]` in `shuffled_message`.
3. Join the list `shuffled_message` into a single string.
4. Return the joined string

⚠️ Common Mistakes

• Incorrectly accessing or modifying indices.
• Not handling the edge case where the message length is 1.

I-mplement

Implement the code to solve the algorithm.

def shuffle(message, indices):
    # Initialize a list to store the shuffled characters
    shuffled_message = [''] * len(message)
    
    # Place each character at the corresponding position
    for i in range(len(message)):
        shuffled_message[indices[i]] = message[i]
    
    # Join the list into a string and return it
    return ''.join(shuffled_message)