03 2021 档案
摘要：Given a binary tree root. Split the binary tree into two subtrees by removing 1 edge such that the product of the sums of the subtrees are maximized.
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摘要：Given the root of a binary tree, each node in the tree has a distinct value. After deleting all nodes with a value in to_delete, we are left with a fo
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摘要：Given the root of a binary tree, each node has a value from 0 to 25 representing the letters 'a' to 'z': a value of 0 represents 'a', a value of 1 rep
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摘要：A tree is an undirected graph in which any two vertices are connected by exactly one path. In other words, any connected graph without simple cycles i
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摘要：Given the root of a binary tree, imagine yourself standing on the right side of it, return the values of the nodes you can see ordered from top to bot
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摘要：Given a reference of a node in a connected undirected graph. Return a deep copy (clone) of the graph. Each node in the graph contains a val (int) and
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摘要：You are given the root of a binary search tree (BST), where exactly two nodes of the tree were swapped by mistake. Recover the tree without changing i
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摘要：Given two integers n and k, return all possible combinations of k numbers out of 1 ... n. You may return the answer in any order. Example 1: Input: n
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摘要：The figure shows the tree view of directories in Windows File Explorer. When a file is selected, there is a file path shown in the above navigation ba
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摘要：A substring is a continuous part of a string. A subsequence is the part of a string that might be continuous or not but the order of the elements is m
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摘要：The Fibonacci sequence Fn is defined by Fn+2=Fn+1+Fn for n≥0, with F0=0 and F1=1. The closest Fibonacci number is defined as the Fib
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摘要：Professional Ability Test (PAT) consists of several series of subject tests. Each test is divided into several levels. Level A is a prerequisite (前置要求
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摘要：The left-view of a binary tree is a list of nodes obtained by looking at the tree from left hand side and from top down. For example, given a tree sho
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摘要：The land is for sale in CyberCity, and is divided into several pieces. Here it is assumed that each piece of land has exactly two neighboring pieces,
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摘要：PP milk （盆盆奶）is Pandas' favorite. They would line up to enjoy it as show in the picture. On the other hand, they could drink in peace only if they bel
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摘要：When the input is much too large to fit into memory, we have to do external sorting instead of internal sorting. One of the key steps in external sort
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摘要：A safari park（野生动物园）has K species of animals, and is divided into N regions. The managers hope to spread the animals to all the regions, but not the s
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摘要：A game of numbers has the following rules: at the beginning, two distinct positive integers are given by the judge. Then each player in turn must give
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摘要：The above picture is from Sina Weibo, showing May 23rd, 2019 as a very cool "Prime Day". That is, not only that the corresponding number of the date 2
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摘要：A proper vertex coloring is a labeling of the graph's vertices with colors such that no two vertices sharing the same edge have the same color. A colo
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摘要：A registration card number of PAT consists of 4 parts: the 1st letter represents the test level, namely, T for the top level, A for advance and B for
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摘要：The "travelling salesman problem" asks the following question: "Given a list of cities and the distances between each pair of cities, what is the shor
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摘要：When shipping goods with containers, we have to be careful not to pack some incompatible goods into the same container, or we might get ourselves in s
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摘要：Werewolf（狼人杀） is a game in which the players are partitioned into two parties: the werewolves and the human beings. Suppose that in a game, player #1
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摘要：In computer science, a heap is a specialized tree-based data structure that satisfies the heap property: if P is a parent node of C, then the key (the
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摘要：This is a problem given in the Graduate Entrance Exam in 2018: Which of the following is NOT a topological order obtained from the given directed grap
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摘要：Given n non-negative integers representing an elevation map where the width of each bar is 1, compute how much water it can trap after raining. Exampl
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摘要：Given an array of distinct integers candidates and a target integer target, return a list of all unique combinations of candidates where the chosen nu
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摘要：You are given an array of k linked-lists lists, each linked-list is sorted in ascending order. Merge all the linked-lists into one sorted linked-list
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摘要：Given the head of a linked list, remove the nth node from the end of the list and return its head. Follow up: Could you do this in one pass? Example 1
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摘要：Given an array nums of n integers and an integer target, find three integers in nums such that the sum is closest to target. Return the sum of the thr
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摘要：Given an array nums of n integers, are there elements a, b, c in nums such that a + b + c = 0? Find all unique triplets in the array which gives the s
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摘要：Write a function to find the longest common prefix string amongst an array of strings. If there is no common prefix, return an empty string "". Exampl
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摘要：Roman numerals are represented by seven different symbols: I, V, X, L, C, D and M. Symbol Value I 1 V 5 X 10 L 50 C 100 D 500 M 1000 For example, 2 is
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摘要：Roman numerals are represented by seven different symbols: I, V, X, L, C, D and M. Symbol Value I 1 V 5 X 10 L 50 C 100 D 500 M 1000 For example, 2 is
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摘要：Implement the myAtoi(string s) function, which converts a string to a 32-bit signed integer (similar to C/C++'s atoi function). The algorithm for myAt
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摘要：Given a signed 32-bit integer x, return x with its digits reversed. If reversing x causes the value to go outside the signed 32-bit integer range [-23
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摘要：The string "PAYPALISHIRING" is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font
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摘要：Given a string s, return the longest palindromic substring in s. Example 1: Input: s = "babad" Output: "bab" Note: "aba" is also a valid answer. Examp
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摘要：vector begin()返回指向第一个元素的迭代器 end()返回指向最后一个元素的迭代器 rbegin()返回指向最后一个元素的迭代器 rend()返回指向第一个元素的迭代器 size()返回容器的元素的个数 max_size()返回容器的最大的元素的个数 resize()重新调整容器的容量，
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摘要：Given a string s containing only digits, return all possible valid IP addresses that can be obtained from s. You can return them in any order. A valid
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摘要：Given an integer array nums of unique elements, return all possible subsets (the power set). The solution set must not contain duplicate subsets. Retu
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摘要：Write a program to solve a Sudoku puzzle by filling the empty cells. A sudoku solution must satisfy all of the following rules: Each of the digits 1-9
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摘要：Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses. Example 1: Input: n = 3 Output: ["((()))","(()
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摘要：The n-queens puzzle is the problem of placing n queens on an n x n chessboard such that no two queens attack each other. Given an integer n, return al
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摘要：Given a string containing digits from 2-9 inclusive, return all possible letter combinations that the number could represent. Return the answer in any
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