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Description A frog is crossing a river. The river is divided into x units and at each unit there may or may not exist a stone. The frog can jump on a 阅读全文
摘要：
description Given a positive integer N, return the number of positive integers less than or equal to N that have at least 1 repeated digit. Example In 阅读全文
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Descpition There are n people and 40 types of hats labeled from 1 to 40. Given a list of list of integers hats, where hats[i] is a list of all hats pr 阅读全文