12 2020 档案
摘要：We have an array of integers, and an array of queries. For the th query , we add val to . Then, the answer to the th query is the sum of the even valu
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摘要：Given two integers and , return any string such that: has length and contains exactly `'a' b` letters, The substring does not occur in , and The subst
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摘要：In a country popular for train travel, you have planned some train travelling one year in advance. The days of the year that you will travel is given
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摘要：Given an array of integers , find the number of triples of indices (i, j, k) such that: `0 这道题给了一个数组，定义了一种三元组，使得这三个数字相‘与’得到为0，问有多少种不同的组合。根据题目中的例子可以发现，
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摘要：Create a timebased key value store class , that supports two operations. 1\. Stores the and , along with the given . 2\. Returns a value such that was
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摘要：On a 2 dimensional , there are 4 types of squares: represents the starting square. There is exactly one starting square. represents the ending square.
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摘要：You are given the root of a binary tree with n nodes where each node in the tree has node.val coins and there are n coins total. In one move, we may c
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摘要：Given an integer array , return the length of a maximum size turbulent subarray of . A subarray is turbulent if the comparison sign flips between each
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摘要：Given an array of positive lengths, return the largest perimeter of a triangle with non zero area, formed from 3 of these lengths. If it is impossible
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摘要：Given an integer array nums sorted in non-decreasing order, return an array of the squares of each number sorted in non-decreasing order. Example 1: I
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摘要：You are given an integer array . From some starting index, you can make a series of jumps. The (1st, 3rd, 5th, ...) jumps in the series are called odd
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摘要：Given an array of integers, return the number of (contiguous, non empty) subarrays that have a sum divisible by . Example 1: Note: 1. `1 这道题给了一个数组，让返回
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摘要：We have a list of on the plane. Find the closest points to the origin . (Here, the distance between two points on a plane is the Euclidean distance.)
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摘要：Given two strings and , each of which represents a non negative rational number, return True if and only if they represent the same number. The string
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摘要：You are given the root of a binary tree with n nodes, where each node is uniquely assigned a value from 1 to n. You are also given a sequence of n val
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摘要：Given two positive integers and , an integer is powerful if it is equal to for some integers and . Return a list of all powerful integers that have va
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摘要：Given an array of integers , sort the array by performing a series of pancake flips. In one pancake flip we do the following steps: Choose an integer
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摘要：Given a binary tree, we install cameras on the nodes of the tree. Each camera at a node can monitor its parent, itself, and its immediate children. Ca
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摘要：Return all non negative integers of length such that the absolute difference between every two consecutive digits is . Note that every number in the a
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摘要：Given a wordlist, we want to implement a spellchecker that converts a query word into a correct word. For a given query word, the spell checker handle
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摘要：Given the root of a binary tree, calculate the vertical order traversal of the binary tree. For each node at position (row, col), its left and right c
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摘要：A binary tree is univalued if every node in the tree has the same value. Return if and only if the given tree is univalued. Example 1: Example 2: Note
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摘要：Given a single positive integer , we will write an expression of the form where each operator , , etc. is either addition, subtraction, multiplication
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摘要：Given a set of points in the xy plane, determine the minimum area of any rectangle formed from these points, with sides not necessarily parallel to th
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