如何实现 Matlab 多重 parfor 循环

parfor i = 1:M
    parfor j = 1:N
        A(i, j) = i + j;
    end
end

parfor ij = 1:M*N
    i = rem(ij, M) + 1;
    j = ceil(ij, M) + 1;
    A(ij) = i + j;
end