Question
On an n x n grid each cell holds 0, 1 (a cherry), or -1 (a thorn you cannot enter). Starting at (0,0), walk to (n-1,n-1) moving only right or down picking up cherries (setting them to 0), then walk back to (0,0) moving only left or up. Return the maximum cherries collected over both trips; if no valid round trip exists, return 0. Start and end cells are never thorns.
cherry_pickup_two_pass(grid: list[list[int]]) → int[[[0,1,-1],[1,0,-1],[1,1,1]]]out5State 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.