Fully Passable Rows and Columns in a Grid

Problem Given a grid of '0' (passable) and '+' (blocked), return the indices of rows that are entirely passable and the indices of columns that are entirely passable.

Input / Output

• Input: an m x n grid of characters '0' and '+'.
• Output: the list of fully-passable row indices and fully-passable column indices.

Constraints

• 1 ≤ m, n ≤ 10^3.

Example

• A row of all '0' → its index is returned; a column containing any '+' is excluded.