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Given a positive integer N, how many ways can we write it as a sum of consecutive positive integers? Example 1: Example 2: Example 3: 分析：https://leetc 阅读全文
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Design a HashMap without using any built-in hash table libraries. To be specific, your design should include these functions: put(key, value) : Insert 阅读全文
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Given an array w of positive integers, where w[i] describes the weight of index i, write a function pickIndex which randomly picks an index in proport 阅读全文
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Given two lists of closed intervals, each list of intervals is pairwise disjoint and in sorted order. Return the intersection of these two interval li 阅读全文
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Design a search autocomplete system for a search engine. Users may input a sentence (at least one word and end with a special character '#'). For each 阅读全文
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We have a list of points on the plane. Find the K closest points to the origin (0, 0). (Here, the distance between two points on a plane is the Euclid 阅读全文