随笔分类 - LeetCode
摘要：You need to construct a binary tree from a string consisting of parenthesis and integers. The whole input represents a binary tree. It contains an int
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摘要：Suppose LeetCode will start its IPO soon. In order to sell a good price of its shares to Venture Capital, LeetCode would like to work on some projects
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摘要：Given a binary tree, return the tilt of the whole tree. The tilt of a tree node is defined as the absolute difference between the sum of all left subt
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摘要：Given an array of 2n integers, your task is to group these integers into n pairs of integer, say (a1, b1), (a2, b2), ..., (an, bn) which makes sum of
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摘要：Think about Zuma Game. You have a row of balls on the table, colored red(R), yellow(Y), blue(B), green(G), and white(W). You also have several balls i
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摘要：Given a picture consisting of black and white pixels, and a positive integer N, find the number of black pixels located at some specific row R and col
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摘要：Given a picture consisting of black and white pixels, find the number of black lonely pixels. The picture is represented by a 2D char array consisting
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摘要：There is a ball in a maze with empty spaces and walls. The ball can go through empty spaces by rolling up (u), down (d), left (l) or right (r), but it
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摘要：You are given a string representing an attendance record for a student. The record only contains the following three characters: A student could be re
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摘要：There is a ball in a maze with empty spaces and walls. The ball can go through empty spaces by rolling up, down, left or right, but it won't stop roll
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摘要：Given a positive 32-bit integer n, you need to find the smallest 32-bit integer which has exactly the same digits existing in the integer n and is gre
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摘要：Given a string, you need to reverse the order of characters in each word within a sentence while still preserving whitespace and initial word order. E
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摘要：There is a brick wall in front of you. The wall is rectangular and has several rows of bricks. The bricks have the same height but different width. Yo
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摘要：There are N students in a class. Some of them are friends, while some are not. Their friendship is transitive in nature. For example, if A is a direct
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摘要：Given a list of strings, you need to find the longest uncommon subsequence among them. The longest uncommon subsequence is defined as the longest subs
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摘要：In the video game Fallout 4, the quest "Road to Freedom" requires players to reach a metal dial called the "Freedom Trail Ring", and use the dial to s
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摘要：Given a group of two strings, you need to find the longest uncommon subsequence of this group of two strings. The longest uncommon subsequence is defi
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摘要：Given two strings representing two complex numbers. You need to return a string representing their multiplication. Note i2 = -1 according to the defin
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摘要：Given an array nums, we call (i, j) an important reverse pair if i < j and nums[i] > 2*nums[j]. You need to return the number of important reverse pai
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摘要：You have n super washing machines on a line. Initially, each washing machine has some dresses or is empty. For each move, you could choose any m (1 ≤
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