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Given an integer matrix, find the length of the longest increasing path. From each cell, you can either move to four directions: left, right, up or do 阅读全文
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Given an array of integers and an integer k, you need to find the total number of continuous subarrays whose sum equals to k. Example 1: Note: 阅读全文
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There are some trees, where each tree is represented by (x,y) coordinate in a two-dimensional garden. Your job is to fence the entire garden using the 阅读全文
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Given a singly linked list, return a random node's value from the linked list. Each node must have the same probability of being chosen. Follow up:Wha 阅读全文
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You are playing the following Nim Game with your friend: There is a heap of stones on the table, each time one of you take turns to remove 1 to 3 ston 阅读全文
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Given an array of scores that are non-negative integers. Player 1 picks one of the numbers from either end of the array followed by the player 2 and t 阅读全文
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There are a total of n courses you have to take, labeled from 0 to n - 1. Some courses may have prerequisites, for example to take course 0 you have t 阅读全文
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Given a char array representing tasks CPU need to do. It contains capital letters A to Z where different letters represent different tasks.Tasks could 阅读全文
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Given an integer array nums, find the sum of the elements between indices i and j (i ≤ j), inclusive. The update(i, val) function modifies nums by upd 阅读全文
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Implement a MyCalendarThree class to store your events. A new event can always be added. Your class will have one method, book(int start, int end). Fo 阅读全文
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Given a binary tree, find the length of the longest path where each node in the path has the same value. This path may or may not pass through the roo 阅读全文
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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 阅读全文
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Given a binary search tree with non-negative values, find the minimum absolute difference between values of any two nodes. Example: Note: There are at 阅读全文
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In this problem, a tree is an undirected graph that is connected and has no cycles. The given input is a graph that started as a tree with N nodes (wi 阅读全文
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In English, we have a concept called root, which can be followed by some other words to form another longer word - let's call this word successor. For 阅读全文
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Given an array of size n, find the majority element. The majority element is the element that appears more than ⌊ n/2 ⌋ times. You may assume that the 阅读全文
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Given two strings s and t, write a function to determine if t is an anagram of s. For example,s = "anagram", t = "nagaram", return true.s = "rat", t = 阅读全文
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Given a string, sort it in decreasing order based on the frequency of characters. Example 1: Example 2: Example 3: 阅读全文
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Write a function to delete a node (except the tail) in a singly linked list, given only access to that node. Supposed the linked list is 1 -> 2 -> 3 - 阅读全文
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Given a char array representing tasks CPU need to do. It contains capital letters A to Z where different letters represent different tasks.Tasks could 阅读全文