How to Design a First Unique Number Class with O(1)?

  • 时间：2020-09-09 14:04:20
  • 分类：网络文摘
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You have a queue of integers, you need to retrieve the first unique integer in the queue. Implement the FirstUnique class: FirstUnique(int[] nums) Initializes the object with the numbers in the queue. int showFirstUnique() returns the val... ...

How to Merge Two List/Iterators in Java?

  • 时间：2020-09-09 14:04:20
  • 分类：网络文摘
  • 阅读：136 次
We have known the approach to merge two linked list in C++. We also know how to apply the merge sort algorithms to merge K sorted list. If you are given two Iterators in Java, how are you supposed to merge them into one list if both iterato... ...

Bruteforce with Memoization to Count the Square Digit Chains

  • 时间：2020-09-09 14:04:20
  • 分类：网络文摘
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A number chain is created by continuously adding the square of the digits in a number to form a new number until it has been seen before. For example, 44 → 32 → 13 → 10 → 1 → 1 85 → 89 → 145 → 42 → 20 → 4 → 16 → 37 → 58 → 89 Therefore any ... ...

Does WIFI Extender Boost Wireless Signal? How to Fix Slow WIFI?

  • 时间：2020-09-09 14:04:20
  • 分类：网络文摘
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In my house, the wireless router is located downstairs, and the PC (HP Z800 is located in my office upstairs. Before I changed to Powerline, the WIFI signal was really weak – It can barely connect to internet (drops often). A WiFi Ext... ...

Finding the Root of a Tree (Finding the Common Destination)

  • 时间：2020-09-09 14:04:20
  • 分类：网络文摘
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You are given the array paths, where paths[i] = [cityAi, cityBi] means there exists a direct path going from cityAi to cityBi. Return the destination city, that is, the city without any path outgoing to another city. It is guaranteed that ... ...

Linear Algorithm to Check If All 1’s Are at Least Length K

  • 时间：2020-09-09 14:04:20
  • 分类：网络文摘
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Given an array nums of 0s and 1s and an integer k, return True if all 1’s are at least k places away from each other, otherwise return False. Example 1: Input: nums = [1,0,0,0,1,0,0,1], k = 2 Output: true Explanation: Each of the 1s... ...

How to Append Another List to a Existing List in Python? (Differ

  • 时间：2020-09-09 14:04:20
  • 分类：网络文摘
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Let’s you have a list in Python: 1 a = [1, 2, 3, 4] a = [1, 2, 3, 4] And you have another list in Python: 1 b = [5, 6, 7, 8] b = [5, 6, 7, 8] You can concatenate two lists by simply using + operator, which will lea... ...

Prefix Sum Algorithm to Count Number of Nice Subarrays

  • 时间：2020-09-09 14:04:20
  • 分类：网络文摘
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Given an array of integers nums and an integer k. A subarray is called nice if there are k odd numbers on it. Return the number of nice sub-arrays. Example 1: Input: nums = [1,1,2,1,1], k = 3 Output: 2 Explanation: The only sub-arrays with... ...

Algorithm to Check if All Points are On the Same Line

  • 时间：2020-09-09 13:16:32
  • 分类：网络文摘
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You are given an array coordinates, coordinates[i] = [x, y], where [x, y] represents the coordinate of a point. Check if these points make a straight line in the XY plane. Input: coordinates = [[1,2],[2,3],[3,4],[4,5],[5,6],[6,7]] Output: ... ...

Depth First Search Algorithm to Compute the Smallest String Star

  • 时间：2020-09-09 13:16:32
  • 分类：网络文摘
  • 阅读：107 次
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 represents ‘b’, and so on. Find the lexicogr... ...