Unit 2 Session 1 (Click for link to problem statements)

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

• Q: What is the problem asking for?

  • A: The problem asks to return a list containing two lists: one with distinct integers from signals1 not in signals2, and one with distinct integers from signals2 not in signals1.

• Q: What are the inputs?

  • A: Two 0-indexed integer arrays signals1 and signals2.

• Q: What are the outputs?

  • A: A list of size 2 where the first element is a list of integers from signals1 not in signals2, and the second element is a list of integers from signals2 not in signals1.

• Q: Are there any constraints on the values in the arrays?

  • A: The integers may appear in any order in the result lists.

Plan the solution with appropriate visualizations and pseudocode.

General Idea: Use sets to find the differences between the two lists and convert the results back to lists.

1. Convert `signals1` and `signals2` to sets `set1` and `set2`. 2. Find the difference between `set1` and `set2` and store it in `diff1`. 3. Find the difference between `set2` and `set1` and store it in `diff2`. 4. Convert `diff1` and `diff2` to lists. 5. Return the list `[diff1, diff2]`.

def find_difference(signals1, signals2): # Step 1: Convert the lists to sets set1 = set(signals1) set2 = set(signals2) # Step 2: Find the difference between the sets diff1 = list(set1 - set2) diff2 = list(set2 - set1) # Step 3: Return the differences as lists return [diff1, diff2]