Reversing the outer loop (starting from N and decrementing) is usually much cleaner and easier to read, reducing the chance of off-by-one math errors.

Use the same loop structure, but inside the inner loop, print the variable 'col' (for 1234, 123) or 'row' (for 4444, 333).

You likely used <= instead of < when checking the boundary, causing the math to yield 0 on the final iteration, or you started counting from 0 instead of 1 without adjusting the math.