答案1
这里是:
\documentclass{scrartcl}
\usepackage{makecell}
\begin{document}
\begin{table}
\centering
\begin{tabular}{c|cc}
\diaghead(-2,1){aaaaaaa}%
{b}{a}&
0&1\\\hline
0&&\\
1&&\\
\end{tabular}
\end{table}
\end{document}
语法是:\diaghead(H ratio,V ratio){Text set for column widthi}{First head}{Second head}
(makecell 手册第 7 节)
(我认为 TikZ 解决方案看起来好多了)