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C1. Make Nonzero Sum (easy version) This is the easy version of the problem. The difference is that in this version the array can not contain zeros. Y 阅读全文
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D1. Balance (Easy version) This is the easy version of the problem. The only difference is that in this version there are no "remove" queries. Initial 阅读全文
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B. Ugu A binary string is a string consisting only of the characters $0$ and $1$. You are given a binary string $s_1 s_2 \dots s_n$. It is necessary t 阅读全文