I'm not sure if this is the right place to post this, but the problem actually belongs to a programming assignment. Solve the recursion: T(0) = 2; T(n) = T(n-1) + 2; Solution: T(n) = 2(n+1) Could someone please show me how they got to that solution? ...
How should I go about removing a given element from a list? As an example, say I have list ['A'; 'B'; 'C'; 'D'; 'E'] and want to remove the element at index 2 to produce the list ['A'; 'B'; 'D'; 'E']? I've already written the following code which accomplishes the task, but it seems rather inefficient to traverse the start of the list whe...
Hello! Is there any fast way to determine the size of the largest strongly connected component in a graph? I mean, like, the obvious approach would mean determining every SCC (could be done using two DFS calls, I suppose) and then looping through them and taking the maximum. I'm pretty sure there has to be some better approach if I on...
Is there a difference between Genetic algorithms and evolutionary algorithms ? I have read multiple papers, talking about genetic or evolutionary algorithms, and while very similar, I think they may not be the same thing. ...
Which data structure used in MySql? ...
Hi, Which data structure can perform insertion, deletion and searching operation in O(1) time in the worst case? We may assume the set of elements are integers drawn from a finite set 1,2,...,n, and initialization can take O(n) time. I can only think of implementing a hash table. Implementing it with Trees will not give O(1) time com...
i know that horners method for polynomial pultiplication is faster but here i dont know what is happening here is code public class horner{ public static final int n=10; public static final int x=7; public static void main(String[] args){ //non fast version int a[]=new int[]{1,2,3,4,5,6,7,8,9,10}; int xi=1; ...
By fuzzy matching I don't mean similar strings by Levenshtein distance or something similar, but the way it's used in TextMate/Ido/Icicles: given a list of strings, find those which include all characters in the search string, but possibly with other characters between, preferring the best fit. ...
I'm tring to find the maximum weight subsequence of an array of positive integers - the catch is that no adjacent members are allowed in the final subsequence. The exact same question was asked here, and a recursive solution was given by MarkusQ thus: function Max_route(A) if A's length = 1 A[0] else maximum of A[0]+Ma...
assume there are three group of high dimension vectors: {a_1, a_2, ..., a_N}, {b_1, b_2, ... , b_N}, {c_1, c_2, ..., c_N}. each of my vector can be represented as: x = a_i + b_j + c_k, where 1 <=i, j, k <= N. then the vector is encoded as (i, j, k) wich is then can be decoded as x = a_i + b_j + c_k. my question is, if there are t...
In cases where order does matter, it's rather easy to generate the matrix of all possible outcomes. One way for doing this is using expand.grid as shown here. What if it doesn't? If I'm right, the number of possible combinations is (S+N-1)!/S!(N-1)!, where S is the number of dice, each with N sides numbered 1 through N. (It is differ...
How to rotate a N x N matrix by 90 degrees. I want it to be inplace? ...
This problem might be relatively simple, but I'm given two text files. One text file contains all encrypted passwords encrypted via crypt.crypt in python. The other list contains over 400k+ normal dictionary words. The assignment is that given 3 different functions which transform strings from their normal case to all different permutat...
Does anyone know where I can find an implementation of an algorithm to convert an activity node graph (aka activity-on-node graph) to an event node graph (aka activiy-on-arrow graph)? If you don't know what I am talking about, take a look here: http://www.brpreiss.com/books/opus7/html/page581.html Please provide a working algo in your ...
Given a phone keypad as shown below: 1 2 3 4 5 6 7 8 9 0 How many different 10-digit numbers can be formed starting from 1? The constraint is that the movement from 1 digit to the next is similar to the movement of the Knight in a chess game. For eg. if we are at 1 then the next digit can be either 6 or 8 if we are at 6 then the ne...
Suppose I have a list of lists of elements which are all the same (i'll use ints in this example) [range(100)[::4], range(100)[::3], range(100)[::2], range(100)[::1]] What would be a nice and/or efficient way to take the intersection of these lists (so you would get every element that is in each of the lists)? For the example that wou...
One of the major strengths of python and a few other (functional) programming languages are the list comprehension. They allow programmers to write complex expressions in 1 line. They may be confusing at first but if one gets used to the syntax, it is much better than nested complicated for loops. With that said, please share with me ...
I need to encrypt a number and I and this encrypted value will be given to a customer ask a key so I want to minimize the number of digits and make them all printable. So I'd like the result to be either all number or all Hex characters. The current encryption method I'm using (for non numbers) converts the characters to hex (2 hex d...
Swanepoel's comment here lead me to this paper. Then, searching for an implementation in C, I came across this, which referenced another paper on an algorithm described here. Both papers describe integer sorting algorithms that run in O(nloglog(n)) time. What is the difference between the two? Have there been any more recent findings ...
Guys, I am looking for a way to convert a base-10 number into a base-N number where N can be large. Specifically i am looking at converting to base-85 and back again. Does anyone know a simple algorithm to perform the conversion? Ideally it would provide something like: to_radix(83992, 85) -> [11, 53, 12] Any ideas are appreciated! ...