随笔分类 - LeetCode
摘要：Given a non-empty 2D matrix matrix and an integer k, find the max sum of a rectangle in the matrix such that its sum is no larger than k. Example: Inp
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摘要：Given a binary tree, collect a tree's nodes as if you were doing this: Collect and remove all leaves, repeat until the tree is empty. Example: Explana
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摘要：Given a nested list of integers, return the sum of all integers in the list weighted by their depth. Each element is either an integer, or a list -- w
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摘要：Design a hit counter which counts the number of hits received in the past 5 minutes. Each function accepts a timestamp parameter (in seconds granulari
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摘要：Given a 2D grid, each cell is either a wall 'W', an enemy 'E' or empty '0' (the number zero), return the maximum enemies you can kill using one bomb.
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摘要：Given a sorted array of integers nums and integer values a, band c. Apply a quadratic function of the form f(x) = ax2 + bx + c to each element x in th
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摘要：Design a logger system that receive stream of messages along with its timestamps, each message should be printed if and only if it is not printed in t
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摘要：Given a non-empty string s and an integer k, rearrange the string such that the same characters are at least distance k from each other. All input str
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摘要：Given a non-negative integer n, count all numbers with unique digits, x, where 0 ≤ x < 10n. Example: Given n = 2, return 91. (The answer should be the
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摘要：Given n points on a 2D plane, find if there is such a line parallel to y-axis that reflect the given points. Example 1: Input: [[1,1],[-1,1]] Output:
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摘要：Design a simplified version of Twitter where users can post tweets, follow/unfollow another user, and is able to see the 10 most recent tweets in the
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摘要：You have a number of envelopes with widths and heights given as a pair of integers (w, h). One envelope can fit into another if and only if both the w
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摘要：Design a Snake game that is played on a device with screen size = width x height. Play the game online if you are not familiar with the game. The snak
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摘要：Given a data stream input of non-negative integers a1, a2, ..., an, ..., summarize the numbers seen so far as a list of disjoint intervals. For exampl
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摘要：Given an Android 3x3 key lock screen and two integers m and n, where 1 ≤ m ≤ n ≤ 9, count the total number of unlock patterns of the Android lock scre
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摘要：Given two arrays, write a function to compute their intersection. Example 1: Input: nums1 = [1,2,2,1], nums2 = [2,2] Output: [2,2] Example 2: Input: n
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摘要：Given two arrays, write a function to compute their intersection. Example 1: Input: nums1 = [1,2,2,1], nums2 = [2,2] Output: [2] Example 2: Input: num
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摘要：Design a Tic-tac-toe game that is played between two players on a n x n grid. You may assume the following rules: A move is guaranteed to be valid and
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摘要：Given a non-empty array of integers, return the k most frequent elements. Example 1: Example 2: Input: nums = [1], k = 1 Output: [1] Example 2: Note:
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摘要：Given a stream of integers and a window size, calculate the moving average of all integers in the sliding window. Example: MovingAverage m = new Movin
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