Here is a sample code for your algorithm using the package algorithm2e
as suggested by your tags:
\documentclass[12pt]{article}
\usepackage[plainruled]{algorithm2e}
\usepackage{amsmath}
\begin{document}
\begin{algorithm}[ht!]
\KwIn{%
$A, B \text{ and } C$
}%
{\bf Initialization:} $\alpha, \beta \text{ and } u$ ;
\While{$|u^{k+1}-u^k | \geq \epsilon$}{%
compute $\alpha$ as $\hat{\alpha}$ with Eq. \eqref{eq:1};
compute $\beta$ as $\hat{\beta}$ with Eq. \eqref{eq:2};
compute $u$ as $\hat{u}$ with Eq. \eqref{eq:3}.
}
\KwOut{%
$\alpha \text{ and } \beta$
}%
\caption{Some algorithm}%
\label{algo:solution}%
\end{algorithm}
\end{document}
And here is what the output looks like:
There are many different options within algorithm2e
to configure the layout of the algorithm. You can for instance replace the option plainruled
by plain
in order to remove the horizontal lines. More information is available in the package documentation here. See section 7.3.
As for the numbering of the algorithm, if you completely remove the number, you will not be able to label it and reference it in the text. Have a look at section 9.2 and the command \SetAlgoRefName
in order to customize the referencing.
algorithm2e
package (which I suppose you are, given your question tags), the default option is without numbering.