随笔分类 - LeetCode
摘要：There is a room with n lights which are turned on initially and 4 buttons on the wall. After performing exactly m unknown operations towards buttons,
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摘要：Given a non-empty special binary tree consisting of nodes with the non-negative value, where each node in this tree has exactly two or zero sub-node.
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摘要：Given a non-negative integer, you could swap two digits at most once to get the maximum valued number. Return the maximum valued number you could get.
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摘要：Given a binary search tree and the lowest and highest boundaries as L and R, trim the tree so that all its elements lies in [L, R] (R >= L). You might
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摘要：Given two integers n and k, you need to construct a list which contains n different positive integers ranging from 1 to n and obeys the following requ
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摘要：If the depth of a tree is smaller than 5, then this tree can be represented by a list of three-digits integers. For each integer in this list: Given a
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摘要：Given an array with n integers, your task is to check if it could become non-decreasing by modifying at most 1element. We define an array is non-decre
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摘要：Given a binary tree with n nodes, your task is to check if it's possible to partition the tree to two trees which have the equal sum of values after r
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摘要：Given a binary tree, write a function to get the maximum width of the given tree. The width of a tree is the maximum width among all levels. The binar
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摘要：Given a 2D integer matrix M representing the gray scale of an image, you need to design a smoother to make the gray scale of each cell becomes the ave
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摘要：You are given an integer array sorted in ascending order (may contain duplicates), you need to split them into several subsequences, where each subseq
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摘要：Given a sorted array, two integers k and x, find the k closest elements to x in the array. The result should also be sorted in ascending order. If the
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摘要：Initially, there is a Robot at position (0, 0). Given a sequence of its moves, judge if this robot makes a circle, which means it moves back to the or
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摘要：You are given an integer array nums with no duplicates. A maximum binary tree can be built recursively from nums using the following algorithm: Create
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摘要：Given a Binary Search Tree and a target number, return true if there exist two elements in the BST such that their sum is equal to the given target. E
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摘要：Given the root of a binary tree, return all duplicate subtrees. For each kind of duplicate subtrees, you only need to return the root node of any one
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摘要：Print a binary tree in an m*n 2D string array following these rules: Example 1: Example 2: Example 3: Note: The height of binary tree is in the range
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摘要：Imagine you have a special keyboard with the following keys: Key 1: (A): Print one 'A' on screen. Key 2: (Ctrl-A): Select the whole screen. Key 3: (Ct
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摘要：Initially on a notepad only one character 'A' is present. You can perform two operations on this notepad for each step: Copy All: You can copy all the
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摘要：In the world of Dota2, there are two parties: the Radiant and the Dire. The Dota2 senate consists of senators coming from two parties. Now the senate
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