Knight Paths on a Phone Keypad (1 to 9 in <=10 Moves)

Problem Overview

On a 9-key phone keypad, a chess knight moves in L-shapes: two keys in one direction, then one key at a right angle. It starts on key 1. Find all possible paths that end on key 9 within 10 moves. What the report says - One phone-screen report, a single…

• The rest of the problem statement — full requirements, constraints, and edge cases
• Approach and trade-offs — what passing candidates did, and the mistakes that sink people