Given n, return n rows of a right triangle filled with alternating 1s and 0s: row i has i values separated by single spaces, odd rows start with 1, even rows start with 0, and values alternate along each row. The pattern is a parityParityWhether a number is even or odd, usually tested with % 2. exercise in disguise — the value in a cell depends only on whether its row number plus column number is even. The second solution trades that formula for a running bit that flips after every cell.