01 2019 档案
摘要：Given a 2D board and a word, find if the word exists in the grid. The word can be constructed from letters of sequentially adjacent cell, where "adjac
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摘要：Given a string containing only digits, restore it by returning all possible valid IP address combinations. Example:
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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 an array of integers nums sorted in ascending order, find the starting and ending position of a given target value. Your algorithm's runtime com
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摘要：Given a sorted array consisting of only integers where every element appears twice except for one element which appears once. Find this single element
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摘要：Given a string s and a string t, check if s is subsequence of t. You may assume that there is only lower case English letters in both s and t. t is po
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摘要：There are a number of spherical balloons spread in two-dimensional space. For each balloon, provided input is the start and end coordinates of the hor
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摘要：Given a collection of intervals, find the minimum number of intervals you need to remove to make the rest of the intervals non-overlapping. Note: Exam
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摘要：Given a string, sort it in decreasing order based on the frequency of characters. Example 1: Example 2: Example 3:
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摘要：Implement a trie with insert, search, and startsWith methods. Example: Note: You may assume that all inputs are consist of lowercase letters a-z. All
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摘要：Given a non-empty array containing only positive integers, find if the array can be partitioned into two subsets such that the sum of elements in both
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摘要：Given a 2d grid map of '1's (land) and '0's (water), count the number of islands. An island is surrounded by water and is formed by connecting adjacen
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摘要：Given a positive integer n, find the least number of perfect square numbers (for example, 1, 4, 9, 16, ...) which sum to n. Example 1: Example 2:
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摘要：Write an efficient algorithm that searches for a value in an m x n matrix. This matrix has the following properties: Integers in each row are sorted i
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摘要：Given an unsorted array of integers, find the length of longest increasing subsequence. Example: Note: There may be more than one LIS combination, it
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摘要：Given an unsorted array of integers, find the length of the longest consecutive elements sequence. Your algorithm should run in O(n) complexity. Examp
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摘要：Given an array with n objects colored red, white or blue, sort them in-place so that objects of the same color are adjacent, with the colors in the or
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摘要：Given a m x n grid filled with non-negative numbers, find a path from top left to bottom right which minimizes the sum of all numbers along its path.
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摘要：Find the kth largest element in an unsorted array. Note that it is the kth largest element in the sorted order, not the kth distinct element. Example
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摘要：Given a set of candidate numbers (candidates) (without duplicates) and a target number (target), find all unique combinations in candidates where the
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摘要：A robot is located at the top-left corner of a m x n grid (marked 'Start' in the diagram below). The robot can only move either down or right at any p
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摘要：Given a binary tree, return the level order traversal of its nodes' values. (ie, from left to right, level by level). For example:Given binary tree [3
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摘要：The thief has found himself a new place for his thievery again. There is only one entrance to this area, called the "root." Besides the root, each hou
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摘要：Given an array nums containing n + 1 integers where each integer is between 1 and n (inclusive), prove that at least one duplicate number must exist.
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摘要：Given a collection of distinct integers, return all possible permutations. Example:
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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 binary tree, return the inorder traversal of its nodes' values. Example: Follow up: Recursive solution is trivial, could you do it iteratively
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摘要：Given a string, your task is to count how many palindromic substrings in this string. The substrings with different start indexes or end indexes are c
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摘要：Suppose you have a random list of people standing in a queue. Each person is described by a pair of integers (h, k), where h is the height of the pers
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摘要：Given a non negative integer number num. For every numbers i in the range 0 ≤ i ≤ num calculate the number of 1's in their binary representation and r
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摘要：Given a set of distinct integers, nums, return all possible subsets (the power set). Note: The solution set must not contain duplicate subsets. Exampl
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