01 2021 档案
摘要：Given a positive integer , return the number of positive integers less than or equal to that have at least 1 repeated digit. Example 1: Input: 20 Outp
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摘要：A conveyor belt has packages that must be shipped from one port to another within D days. The ith package on the conveyor belt has a weight of weights
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摘要：You are given a list of songs where the ith song has a duration of seconds. Return the number of pairs of songs for which their total duration in seco
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摘要：Every non negative integer has a binary representation. For example, can be represented as in binary, as in binary, and so on. Note that except for ,
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摘要：Return the root node of a binary search tree that matches the given traversal. (Recall that a binary search tree is a binary tree where for every node
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摘要：In a row of dominoes, and represent the top and bottom halves of the domino. (A domino is a tile with two numbers from 1 to 6 one on each half of the
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摘要：Normally, the factorial of a positive integer is the product of all positive integers less than or equal to . For example, . We instead make a clumsy
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摘要：Given an array of integers, we must modify the array in the following way: we choose an and replace with , and we repeat this process times in total.
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摘要：Given an array of 0s and 1s, we may change up to values from 0 to 1. Return the length of the longest (contiguous) subarray that contains only 1s. Exa
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摘要：Given a string , determine if it is valid. A string is valid if, starting with an empty string , you can transform into after performing the following
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摘要：Given an array of strings made only from lowercase letters, return a list of all characters that show up in all strings within the list (including dup
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摘要：You are given a grid of size N x N, and each cell of this grid has a lamp that is initially turned off. You are also given an array of lamp positions
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摘要：On an 8 x 8 chessboard, there is one white rook. There also may be empty squares, white bishops, and black pawns. These are given as characters 'R', '
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摘要：We are given the node of a maximum tree: a tree where every node has a value greater than any other value in its subtree. Just as in the "previous pro
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摘要：In a town, there are people labelled from to . There is a rumor that one of these people is secretly the town judge. If the town judge exists, then: 1
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摘要：Given an array of non negative integers, the array is squareful if for every pair of adjacent elements, their sum is a perfect square. Return the numb
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摘要：You are given an `grid` where each cell can have one of three values: representing an empty cell, representing a fresh orange, or representing a rotte
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摘要：In a binary tree, the root node is at depth , and children of each depth node are at depth . Two nodes of a binary tree are cousins if they have the s
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摘要：Given an array of positive integers, call a (contiguous, not necessarily distinct) subarray of good if the number of different integers in that subarr
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摘要：On a broken calculator that has a number showing on its display, we can perform two operations: Double: Multiply the number on the display by 2, or; D
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摘要：Given two strings and , return the length of their longest common subsequence. A subsequence of a string is a new string generated from the original s
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摘要：Given an array equations of strings that represent relationships between variables, each string has length and takes one of two different forms: or .
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摘要：For a non negative integer , the array form of is an array of its digits in left to right order. For example, if , then the array form is . Given the
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摘要：Given the of a binary tree, each node has a value from to representing the letters to : a value of represents , a value of represents , and so on. Fin
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摘要：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
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