Swap Nodes In Pairs

Problem Highlights

• 🔗 Leetcode Link: https://leetcode.com/problems/swap-nodes-in-pairs/
• 💡 Problem Difficulty: Medium
• ⏰ Time to complete: __ mins
• 🛠️ Topics: Linked Lists, Recursion
• 🗒️ Similar Questions: Swapping Nodes in a Linked List

1: 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?

Run through a set of example cases:

HAPPY CASE



EDGE CASE

2: M-atch

Match what this problem looks like to known categories of problems, e.g. Linked List or Dynamic Programming, and strategies or patterns in those categories.

• Multiple passes: To find the length, or save other information about the contents
• Two pointers: ‘Race car’ strategy with one regular pointer, and one fast pointer
• Dummy node: Helpful for preventing errors when returning ‘head’ if merging lists, deleting from lists

3: P-lan

Plan the solution with appropriate visualizations and pseudocode.

General Idea:

⚠️ Common Mistakes

4: I-mplement

Implement the code to solve the algorithm.

5: R-eview

Review the code by running specific example(s) and recording values (watchlist) of your code's variables along the way.

• Trace through your code with an input to check for the expected output
• Catch possible edge cases and off-by-one errors

6: E-valuate

Evaluate the performance of your algorithm and state any strong/weak or future potential work.

• Time Complexity:
• Space Complexity: