Question
Mark the open floor cells named in a coordinate list and return the resulting grid, leaving walls, the start, and the exit exactly as they were. ```python def solve(raw: str) -> str: ... ``` ## Requirements - Line 1 is `rows cols`. The next `rows` lines are the grid, each exactly `cols` characters long. - A count follows the grid, then that many lines of `row col`. - Coordinates are zero-based and name the row first, then the column. - Replace a `.` at a listed coordinate with `*`. If the cell holds `S`, `E`, `#`, or is already `*`, leave it unchanged. - Listing the same coordinate again has no additional effect. - Return the whole grid with each row on its own line, rows separated by a newline, and no extra text. - Every coordinate is inside the grid. - Do not append a trailing newline to the returned string; return the value exactly once.