function [L U]=Crout_1(A)
% Factorización LU por Crout
 n=size(A,1);
   for k=1:n
       i=k:n;   A(i,k)=A(i,k)-A(i,1:k-1)*A(1:k-1,k);
       i=k+1:n; A(k,i)=(A(k,i)-A(k,1:k-1)*A(1:k-1,i))/A(k,k);
   end
   L=tril(A,0); U=triu(A,1)+eye(n,n);
end