Problem Merge sorted linked lists and return it as one sorted list. Analyze and describe its complexity. Example: Input: [ 1->4->5, 1->3->4, 2->6 ] Output: 1->1->2->3->4->4->5->6 Input lists - an array of linked list pointers # Definition for singly-linked list.
0 CommentsGiven two linked list nodes, one might overlap the other. That is, one linked list might contain a sequence that is already in the other linked list. The two linked lists share a common node.
0 CommentsSingly linked lists can be tricky in its own right. Without the convenience of having a pointer to the previous node that is provided in doubly-linked lists, it can be really easy to be wasteful in performance with singly linked lists.
0 CommentsProblem Detect a cycle in a linked list and return the node that represents the start of the cycle. Input head: a pointer to the linked list Approach First, lets concentrate on how to detect a cycle in a linked list.
0 Comments... result is not a 0, then the bit at is a 1. Strings When constructing strings, use a list in Python and add characters accordingly. The entire string can be returned via "".
0 CommentsThere are two practical ways to square each element of a list, and return the new list. For example, if we input a List(5, 10), we should have a List(25, 100).
0 Comments... and an integer index to keep track of which digit you need to convert. Start by having an empty list. The goal is to have a list representing a mnemonic; with digits and characters.
0 Comments... all occurrences of a space with a string Linked Lists Reversing sublists of singly linked lists Cycles in singly linked lists Overlapping singly linked lists Merging two sorted singly linked lists Merge k sorted lists Recursion Counting the path of sums Money Denominations Phone Number Mnemonics Unique Permutation Dynamic Programming Perfect Squares Find the Maximum Min Path Binary Trees Tree Symmetry Iterative In-Order Traversal of a Binary Tree Construct a Binary Tree from Pre-Order Traversal and In-Order Traversal BST Validate a BST Binary Heaps Merge k sorted lists Graphs Find a path in a maze from start to finish Flip colors in a matrix Search Search in a rotated sorted array Find the Duplicate Number Greedy Algorithms Queue Reconstruction By Height Trie Build a Trie in Python Invariant Compute the max.
0 Commentsvar jsav = new JSAV("ll"); jsav.label("Two sorted lists"); var ll1 = jsav.ds.list(); var ll2 = jsav.ds.list(); ll1.addLast("5").addLast("7").
0 CommentsThis is an array/list trick that saves about O(n) in space complexity by taking advantage of a given array with integers representing indices. For this example problem, suppose that we want to apply some permutation P to an array A.
0 Comments... the total number of money denominations, given 2 parameters -- the amount of money and the list of allowed coins to use. But not only that, we can also make this a one-liner! def countChange(money: Int, coins: List[Int]): Int = if(money == 0) 1 else if(money > 0 && !coins.
0 Comments... since we don't want to store hash tables into hash tables 😦. A good compromise is to convert the list objects into immutable tuple objects. An alternative solution is a string, but converting a list to a string will involve a .
0 Comments... C, D, E] We should also have our edges defined somewhere. Edges are best defined in an adjacency list, which should be used to represent the neighbors of a vertex. Starting Point Once we have our vertices defined, we can now define an algorithm that accounts for all vertices in the highest-level view so that all nodes and edges in the graph are accounted for.
0 CommentsProblem 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 person and k is the number of people in front of this person who have a height greater than or equal to h.
0 Comments... => ['a','b','c'] "a.b.c".split(".", maxsplit=1) => `['a','b.c'] When you want a list with entries delimited by some separator. Note that, the delimiter will not be included in the result.
0 Comments... structure, which stands for n-dimensional array. The key difference between a traditional Python list and ndarray is Python lists can allow any type of object inside the list.
0 Comments... resumes code execution. This is useful when you are iterating through large sets of data (i.e. a list of billions of objects) which takes up more memory than you have available on your machine running the Python code.
0 Comments... the children gets added before the parent, which if done recursively, will present you with a list of nodes in topological order. BFS To do topological sort via BFS, you will need two things: Adjacency Lists In-degree array (or map) The N-degree (or in-degree) array is a mapping of indices (the vertex ID) to the count of incoming graph edges.
0 Comments... users in the CE community provide cheat tables for games. These cheat tables are basically lists of memory addresses that directly correspond to certain data in a game, e.g. movement speed, or health points.
0 Comments... on each element in some container and transform them. For example, if I want to convert a list of numbers to strings in Javascript: [0, 1, 2, 3].map(number => Integer.parseInt(number)); Reduce Reduce is also known as folding or aggregation.
0 Comments... is. From the wiki: An index ( plural: usually indexes, more rarely indices; see below) is a list of words or phrases ('headings') and associated pointers ('locators') to where useful material relating to that heading can be found in a document or collection of documents.
0 Comments... = A[~j][i] return copy Note that ~j is equivalent to -(j + 1). When used as an index of a list, it could also be interpreted as j + 1 values from the right. This algorithm requires space complexity and time complexity Approach #2 The optimized approach has a very straightforward strategy that you can follow.
0 Comments... Firefox, and Internet Explorer. Event Loop The event loop is basically a loop that listens for an event and takes some action when an event is received. while (queue.waitForMessage()) { queue.
0 Comments... Data Structures Empty array ArrayList<T> list = new ArrayList<>(); Array with values ArrayList<Integer> list = new ArrayList<>(Arrays.
0 Comments... the left) that is smaller than the current max_so_far, we calculate the profit and add it to the list -- more precisely at the index of the element we just looked at. All that needs to be done now, is to add the th element in the forward iteration to the th element in the backward iteration.
0 Comments... means is not a prime. Problem Given an integer , write a function that returns a list of all prime numbers up to (inclusive). Input : Integer Examples prime_func(5) => [2, 3, 5] prime_func(10) => [2, 3, 5, 7] prime_func(0) => [] Strategy A quick, brute-force way to solve this is to go through all numbers from to and evaluate each number if it is a prime.
0 Comments... Thus, when thinking about the iterative approach, we should simply use a stack data structure. A list does the trick here. Even with a list however, it is still a bit tricky to represent recursive logic in an iterative fashion.
0 CommentsProblem Given a collection of intervals, merge all overlapping intervals. Example 1: Input: [[1,3],[2,6],[8,10],[15,18]] Output: [[1,6],[8,10],[15,18]] Explanation: Since intervals [1,3] and [2,6] overlaps, merge them into [1,6].
0 Comments... , so we return . Fun fact: This is similar to detecting a cycle in a linked list. If you treat the integer values of the array as pointers, then running into the same pointer value implies that a cycle exists.
0 Comments... of ChapterTitles. Frank wants to design a class now, called TableOfContents that houses a list of Chapter objects or ChapterTitle objects. But storing a list of entries isn't enough; Frank wants the TableOfContents class to be smart enough to know how to handle a Chapter or a ChapterTitle when needed.
0 CommentsProblem Given a pre-order traversal array of integers and an in-order traversal array of integers, construct a binary tree. Input preorder - array of integers inorder - array of integers # Definition for a binary tree node.
0 Comments... word space where you can (less typing) Step-by-step + bullet point style is better than numbered lists (i.e. 1. Draw, 2. Pseudocode 3. Run Test Cases). It is more work to update numbered lists if you miss a step.
0 Comments... sec = 60 minutes = 1 hour 24 * 3600 = 1440 minutes = 24 hours = 1 day Here is a ballpark list for various content: URLs: Images: (avg.), (max) Videos: (avg.
0 Comments... assignment): # AC-3 """ initialize the queue with all the arcs in csp""" # queue = list of arcs (i.e. an arc from Chad to Egypt) queue = [] # tail represents a country for tail in csp : # curr represents a country adjacent to tail # add arcs from tail -> (adjacent countries to tail) to the queue for curr in csp[tail]: queue.
0 Comments... the other two because it's a one-way street for input data, but what if someone already had a list of hashed passwords for the most commonly used passwords? (Hint: it's already exists somewhere on the web) Another key thing is that your typical hash (MD5, SHA-256) is incredibly fast to execute, because their purpose is to verify file hash checksum integrities.
0 Comments... to work with mutable strings We can use bytearray to manipulate strings in a fashion similar to lists. String index assignment can be done with bytearray. i.e. s[0] = ord('A') ord returns an integer representing the Unicode code point of that character.
0 Comments... to the right of were already in descending order; all we have to do is reverse that sublist to get them into ascending order. Solution def nextPermutation(self, nums: 'List[int]') -> 'None': """ Do not return anything, modify nums in-place instead.
0 Comments... and public key. It then checks whether or not the SSL certificate is trusted, by checking against list of trusted CAs. If the certificate is trusted, the browser creates a symmetric session key using the server's public key and sends it to the server.
0 Comments... are major scaling drawbacks to this, as well as resiliency issues. For that reason, it is hard to list that as a runner-up. :( Solutions: Object Store (ex: Amazon S3) + CDN Runner-ups: - Text Autocomplete Service Text autocomplete is so popular that a solution was made specifically for it - search engines.
0 CommentsProblem An array of integers naturally defines a set of lines parallel to the Y-axis, starting from x = 0 as illustrated in the figure above. The goal of this problem is to find the pair of lines that together with the X-axis "trap" the most water.
0 Comments... fetch or update resources on the server. This standard allows two things: The server can whitelist a list of IPs so that any request from these IPs can access the resources.
0 CommentsThis is a personal list of useful resources for improving web stacks, frameworks, development, UX, whatever that I come across! Software Engineering The Absolute Minimum Every Software Developer Absolutely, Positively Must Know About Unicode and Character Sets (No Excuses!) Encryption vs.
0 Comments... if you'd like (say, 2 or 3 digits => 100 or 1000 partitions). This counter, as well as the known list of hotspot keys, must be tracked or bookmarked somewhere in the application logic.
0 Comments... are two ways. The first way is 2PC, or Two-Phase Protocol, which is not recommended for reasons listed here. The other way is consensus, where all participant nodes can use a consensus algorithm to a.
0 Comments