Code Room
CodingMediumcod-g269
Subject Probability dpLevel Mid–Senior~30 minCommon in Algorithms & data structures interviewsIndustries Software development

Question

On an N x N chessboard a knight starts at cell (r, c) and makes exactly K moves, each chosen uniformly at random among the 8 knight moves (even if it would leave the board, in which case the knight falls off and stops). Return the probability the knight is still on the board after K moves, rounded to 6 decimals. 1 <= N <= 25, 0 <= K <= 100, 0 <= r,c < N.

Implement
knight_on_board(N: int, K: int, r: int, c: int) → float
Examples
in[3,2,0,0]out0.0625
What a strong answer looks like

State your approach and its time/space complexity out loud before you optimize. Handle the edge cases (empty input, duplicates, overflow), and say why you chose this over the brute force. Green tests are the floor, not the grade.

Vibe coding: describe the solution in plain language (or narrate it) and the coach grades your approach. Generating runnable code from your description is coming next.

Run or narrate your approach, then ask the coach.