Floats change behavior when using package "algorithm"

Question

Not really a problem, but I noticed this when pruning stuff from a document preamble to find a problem I was having. I've found the problem but also something a bit weird

Just the act of importing the package algorithm is changing the position of floats (I've tested tables and figures)

\documentclass[]{article}

\usepackage{algorithm}

\begin{document}
    \begin{table}[H]
        \caption{I'm here}
    \end{table}
\end{document}

If I comment the \usepackage{algorithm} line, the caption moves from the top of the page to the middle

Would there be conflicts between definitions or something? Is it normal/acceptable for this to happen?

I've tested this with pdflatex and xelatex and it behaves the same way

Answer 1

algorithm uses the float package which defines a H float specifier. Without loading algorithm, your

\begin{table}[H]
  ...
\end{table}

actually produces an error stating "Unknown float option H".

LaTeX does recover from this error though and then defaults to something different, which changes the display to a page-of-floats-like layout (which has the float centred vertically).