Question
You are given an n x n grid where grid[r][c] is the elevation of cell (r,c). At time t the water level is t, and you can be at cell (r,c) only if grid[r][c] <= t. From the top-left cell you may move to a 4-directionally adjacent cell instantly if both cells are below the current water level. Return the least time t at which you can reach the bottom-right cell. (Equivalently, minimize the maximum elevation along a path from corner to corner.)
swim_in_water(grid: list[list[int]]) → int[[[0,2],[1,3]]]out3State 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.