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题目如下： We write the integers of A and B (in the order they are given) on two separate horizontal lines. Now, we may draw connecting lines: a straight l 阅读全文
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题目如下： Given a list of words, each word consists of English lowercase letters. Let's say word1 is a predecessor of word2 if and only if we can add exac 阅读全文
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题目如下： Given a string S of lowercase letters, a duplicate removal consists of choosing two adjacent and equal letters, and removing them. We repeatedly 阅读全文
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题目如下： We have a collection of rocks, each rock has a positive integer weight. Each turn, we choose the two heaviest rocks and smash them together. Sup 阅读全文