I need to find the shortest path in a graph with the least number of added nodes. The start and end nodes are not important. If there is no path in a graph just between specified n-nodes, I can add some nodes to complete the shortest tree but I want to add as few new nodes as possible. What algorithm can I use to solve this problem? ...
I wanna make the Mel-Frequency Cepstrum Algorithm but there are some things that I don't understand. After FTT is done we need to "Map the powers of the spectrum obtained above onto the mel scale, using triangular overlapping windows." I know how to calculate the triangles and I also know how to pass to mel scale. I simply don't know w...
We have a list of x,y pairs. Every pair represents a point on a 2D space. I want to find the closest point from this list, to a specific point xq,yq. What is the best performance-critical algorithm for this problem? Lisp of points is not going to change; which means I do not need to perform insertion and deletion. I want just to find the...
All, I THINK that I'm looking for a function for Trilinear interpolation. Here's the details: I have a three dimensional dataset: Dimension 1 varies from 0 to 100 in increments of 5 Dimension 2 varies from 0 to 100 in increments of 5 Dimension 3 varies from 0 to 1 in increments of 0.1 So, I have 4851 total values (21 x 21 x 11). ...
I have a directed graph, what algorithm can i use to find the number of distinct acyclic paths between 2 particular vertices, and count the maximum times any path is used in these distinct paths? Two paths are distinct if they either visit a different number of vertices or visit vertices in a different order. ...
Hi, This is the problem described in Programming pearls. I can not understand binary search method descrbied by the author. Can any one helps to elaborate? Thanks. EDIT: I can understand binary search in general. I just can not understand how to apply binary search in this special case. How to decide the missing number is in or not in...
Can anyone tell me order of complexity of below algorithm? This algorithm is to do following: Given an unsorted array of integers with duplicate numbers, write the most efficient code to print out unique values in the array. I would also like to know What are some pros and cons in the context of hardware usage of this implementation ...
I have around 100 megabytes of text, without any markup, divided to approximately 10,000 entries. I would like to automatically generate a 'tag' list. The problem is that there are word groups (i.e. phrases) that only make sense when they are grouped together. If I just count the words, I get a large number of really common words (is, t...
At work, we are given a set of constraints of the form (taskname, frequency) where frequency is an integer number which means the number of ticks between each invocation of the task "taskname". Two tasks cannot run concurrently, and each task invocation takes one tick to complete. Our goal is to find the best schedule in terms of matchin...
I have a list of sets (a,b,c,d,e in below example). Each of the sets contains a list of nodes in that set (1-6 below). I was wondering that there probably is a general known algorithm for achieving the below, and I just do not know about it. sets[ a[1,2,5,6], b[1,4,5], c[1,2,5], d[2,5], e[1,6], ] I would like to generate a new s...
Here is the problem from code chef : A set of N dignitaries have arrived in close succession at Delhi and are awaiting transportation to Roorkee to participate in the inaugural ceremony of Cognizance. Being big sponsors of Cognizance, it has been deemed unsuitable by the organizing team to arrange for more than one dignitary to travel ...
I'm trying to work out how to efficiently sort a huge dataset that won't fit in memory. The obvious answer at a high level is to sort a whole bunch of chunks that do fit in memory using some standard algorithm, write these out to disk, and then merge them. Merging them is the problem. Let's say the data divides up into C chunks, so I ...
While I write an algorithm, I may not come know that this is some special kind of algorithm strategy which is developed earlier and named as xxxx or whatever. I'll try to illustrate my point: Brute-force search or exhaustive search, also known as generate and test, is a trivial but very general problem-solving technique that consists of...
Can people recommend quick and simple ways to combine the hash codes of two objects. I am not too worried about collisions since I have a Hash Table which will handle that efficiently I just want something that generates a code quickly as possible. Reading around SO and the web there seem to be a few main candidates: XORing XORing wi...
There is a LEDA program. http://www.algorithmic-solutions.com/ which basically provides GUI to algorithms. I d like to get into that, I was curious if I can code with C# or JAVA for LEDA. I have looked at their website and googled it. But i didnt see any other languages beside c/c++, Does anyone know if i can use C# or Java for LEDA...
Does anyone know how Java implements its hash tables (HashSet or HashMap)? Given the various types of objects that one may want to put in a hash table, it seems very difficult to come up with a hash function that would work well for all cases. ...
I am writing a daemon that utilizes inotify to monitor file access and it is critical that I don't miss anything on a recursive search. I found this interesting idea and have begun to implement it. ftw() and ftw64() do not use a breadth-first algorithm, its more "pre-order". nftw() gives me the option of depth-first, but I'm worried abo...
Given a dictionary (just a list of strings). You receive a feed of an unknown number of letters from an external source. Given the string of letters, how would you go about listing all valid words (from the diciontary) you can make from any combination from those letters. So if you receive: abpplead You should find apple, bad, pad, le...
I've got a list of images with dimensions for each image. I need to select and layout a group of images from that list so they fit on screen with slight overlaps, and no gaps. (gradient in the overlap to avoid a sharp transition) I've researched 2d box packing algorithms, but they all assume that you need to use all the items, and, of c...
I'm trying to figure out an algorithm to find the highest 2 numbers in a list of numbers. The highest number can be found in n-1 stages, perhaps by doing the fist step of a bubble sort or something along those lines. To me it seems that finding the next highest number as well could be found in a total of 1.5n comparisons on average. ...