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问题描述： Convert a non-negative integer to its english words representation. Given input is guaranteed to be less than 231 - 1. For example, 阅读全文
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问题描述： Write a program to check whether a given number is an ugly number. Ugly numbers are positive numbers whose prime factors only include 2, 3, 5. F 阅读全文
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问题描述： Given an integer, convert it to a roman numeral. Input is guaranteed to be within the range from 1 to 3999. 分析： /** * 将一个Integer数字转换为罗马数字，范围 1-3 阅读全文
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问题描述： Given a roman numeral, convert it to an integer. Input is guaranteed to be within the range from 1 to 3999. 算法： /** * 输入一个罗马数字，返回它的整型表示 * @autho 阅读全文
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问题描述： Given a sorted integer array without duplicates, return the summary of its ranges. For example, given [0,1,2,4,5,7], return ["0->2","4->5","7"]. 阅读全文