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题目：Given a string, find the length of the longest substring without repeating characters. 思路：用一个表（数组）来存储字符在字符串中的位置。因为字符本质上是一个unicode数字，因此建立一个数组，数组的下标表 阅读全文
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题目： Given a sorted array nums, remove the duplicates in-place such that each element appear only once and return the new length. Do not allocate extra 阅读全文
摘要：
题目： You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order and each of their nodes co 阅读全文