# rotl90(A)

rotl90(A)

Rotate matrix `A` left 90 degrees.

## Examples

1. Rotate a matrix left 90 degrees:

``````julia> A = [1 2 3; 4 5 6; 7 8 9];
julia> rotl90(A)
3×3 Array{Int64,2}:
3  6  9
2  5  8
1  4  7``````

This example rotates the matrix `A` left 90 degrees.

2. Rotate a matrix left 90 degrees multiple times:

``````julia> B = [11 12; 21 22];
julia> rotl90(B, 2)
2×2 Array{Int64,2}:
22  21
12  11``````

It rotates the matrix `B` left 90 degrees twice.

3. Handle zero rotations (equivalent to copy):
``````julia> C = [1 2 3; 4 5 6; 7 8 9];
julia> rotl90(C, 0)
3×3 Array{Int64,2}:
1  2  3
4  5  6
7  8  9``````

When `k` is zero, the function returns a copy of the original matrix.

Common mistake example:

``````julia> D = [4 5; 6 7];
julia> rotl90(D, 5)
ERROR: DomainError: The rotation count must be a non-negative integer less than 4.``````

In this example, the rotation count `k` is greater than or equal to 4, which is not allowed. The valid range for `k` is 0 to 3. Make sure to provide a valid rotation count within this range to avoid errors.