摘要：
Given a roman numeral, convert it to an integer.Input is guaranteed to be within the range from 1 to 3999.Solution：此题是要求把罗马数字转换成数字。首先，学习一下罗马数字，参考罗马数字罗... 阅读全文
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Given a sorted array and a target value, return the index if the target is found. If not, return the index where it would be if it were inserted in or... 阅读全文
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Implementatoito convert a string to an integer.Hint:Carefully consider all possible input cases. If you want a challenge, please do not see below and ... 阅读全文
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The count-and-say sequence is the sequence of integers beginning as follows:1, 11, 21, 1211, 111221, ...1is read off as"one 1"or11.11is read off as"tw... 阅读全文
摘要：
Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases.For example,"A man, a plan, a canal: Pana... 阅读全文