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

• 💡 Difficulty: Easy
• ⏰ Time to complete: 5 mins
• 🛠️ Topics: Functions, Lists, Loops

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

• Q: What should the function return if the villain is not found in the crowd?

  • A: The function should return an empty list [].

• Q: How does the function handle multiple occurrences of the villain in the crowd?

  • A: The function should return a list of all indices where the villain is found.

• The function find_villain(crowd, villain) should return a list of indices where the villain is found in the crowd.

HAPPY CASE Input: lst = ['Batman', 'The Joker', 'Alfred Pennyworth', 'Robin', 'The Joker', 'Catwoman', 'The Joker'], target = 'The Joker' Expected Output: [1, 4, 6] EDGE CASE Input: lst = [], target = 'The Joker' Expected Output: [] Input: lst = ['Batman', 'Superman'], target = 'The Joker' Expected Output: [] 

Plan the solution with appropriate visualizations and pseudocode.

General Idea: Iterate through the crowd list, checking each element against the villain, and store the indices where they match.

1. Define the function `find_villain(crowd, villain)`. 2. Initialize an empty list `indices` to store matching indices. 3. Use a loop to iterate through `crowd` with an index counter. 4. For each person in `crowd`, check if they match `villain`. 5. If they match, append the current index to `indices`. 6. Return the `indices` list.

⚠️ Common Mistakes

• Forgetting to initialize the indices list.
• Not incrementing the index counter correctly.

Implement the code to solve the algorithm.

def find_villain(crowd, villain): # Initialize an empty list to store the indices indices = [] # Initialize the index counter index = 0 # Iterate through the crowd list for person in crowd: # Check if the current person is the villain if person == villain: # If so, append the current index to the indices list indices.append(index) # Increment the index counter index += 1 # Return the list of indices return indices