A finite word $w$ is called \emph{rich} if it contains $\vert w\vert+1$ distinct palindromic factors including the empty word. For every finite rich word $w$ there are distinct nonempty palindromes $w_1, w_2,\dots,w_p$ such that $w=w_pw_{p-1}\cdots w_1$ and $w_i$ is the longest palindromic suffix of $w_pw_{p-1}\cdots w_i$, where $1\leq i\leq p$. This palindromic factorization is called \emph{UPS-factorization}. Let $luf(w)=p$ be \emph{the length of UPS-factorization} of $w$. In 2017, it was proved that there is a constant $c$ such that if $w$ is a finite rich word and $n=\vert w\vert$ then $luf(w)\leq c\frac{n}{\ln{n}}$. We improve this result as follows: There are constants $\mu, \pi$ such that if $w$ is a finite rich word and $n=\vert w\vert$ then \[luf(w)\leq \mu\frac{n}{e^{\pi\sqrt{\ln{n}}}}\mbox{.}\] The constants $c,\mu,\pi$ depend on the size of the alphabet.
翻译:限定单词 $w$ 如果它包含 $w_www} {vert w\vert+1$, 包括空单词。 对于每个限定的丰富单词 $w$, 它有明显的非空的白金币 $_1, w_2,\dots, w_p$_pw$, 美元是1美元, $w_ wwwww+1 cdots w_ 美元, 包括空单数。 对于每个限定的丰富单词, 包括空数 $。 对于每个有限的富单词, $w_ w_vert+1$, 包括空数。 对于每个富裕单词 $1, w_w_w, 2,\\\dddt, w_p$, 因此, 美元是固定的, 美元是固定的。