For a word S, let f(S) be the largest integer m such that there are two disjoint identical (scattered) subwords of length m. Let f(n, σ) = min{f(S): S is of length n, over alphabet σ}. Here, it is shown that. 2f(n,{0,1})=n-o(n) using the regularity lemma for words. In other words, any binary word of length n can be split into two identical subwords (referred to as twins) and, perhaps, a remaining subword of length o(n). A similar result is proven for k identical subwords of a word over an alphabet with at most k letters.
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机译:对于单词S,令f(S)为最大整数m,以便有两个长度为m的不相交的相同(分散)子词。令f(n,σ)= min {f(S):S在字母σ}上的长度为n。在此显示。 2f(n,{0,1})= n-o(n)使用单词的正则性引理。换句话说,任何长度为n的二进制字都可以分为两个相同的子字(称为对子),也可以拆分为长度为o(n)的剩余子字。对于在最多具有k个字母的字母表中的一个单词的k个相同子词,证明了类似的结果。
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