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hashmap map key and value for highly efficient lookup.hashmap search used binary tree O(log2)main methodsint size();hashmap.put(key,value);Value get(k... 阅读全文
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Rotate ListGiven a list, rotate the list to the right bykplaces, wherekis non-negative.For example:Given1->2->3->4->5->NULLandk=2,return4->5->1->2->3-... 阅读全文
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Reverse Nodes in k-GroupGiven a linked list, reverse the nodes of a linked listkat a time and return its modified list.If the number of nodes is not a... 阅读全文
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Linklist定义：node includes pointer(next) and value区别（与Array）:Array has indice,which is in sequence,LinkList has pointer to next.single list and double l... 阅读全文
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Then-queens puzzle is the problem of placingnqueens on ann×nchessboard such that no two queens attack each other.Given an integern, return all distinc... 阅读全文
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博主忙毕业的事情，一个半月木有刷题，感觉手都生了....今天开始闭关修炼～～先拿道简单的题练练手Two Sum（熟悉吧熟悉吧）Given an array of integers, find two numbers such that they add up to a specific target... 阅读全文
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MySQL top（MySQL limit）语法SELECT column_name(s)FROM table_nameLIMIT number例子SELECT *FROM PersonsLIMIT 5SQL LIKE 操作符SQL LIKE 操作符语法SELECT column_name(s)FR... 阅读全文
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Determine if a Sudoku is valid, according to:Sudoku Puzzles - The Rules.The Sudoku board could be partially filled, where empty cells are filled with ... 阅读全文
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SQL SELECT 语句如需获取名为 "LastName" 和 "FirstName" 的列的内容（从名为 "Persons" 的数据库表），请使用类似这样的 SELECT 语句：SELECT LastName,FirstName FROM Persons"Persons" 表:IdLastNam... 阅读全文
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Given a non-negative number represented as an array of digits, plus one to the number.The digits are stored such that the most significant digit is at... 阅读全文