I am programming an algorithm where I have broken up the surface of a sphere into grid points (for simplicity I have the grid lines parallel and perpendicular to the meridians). Given a point A, I would like to be able to efficiently take any grid "square" and determine the point B in the square with the least spherical coordinate distan...
Hi there, I have a logical statement that says "If everyone plays the game, we will have fun". In formal logic we can write this as: Let D mean the people playing. Let G be the predicate for play the game. Let F be the predicate for having fun. Thus [VxeD, G(x)] -> [VyeD, F(y)] V is the computer science symbol for universal quantifi...
If one computer can only hold 1 million numbers, how to find out the median number from 100 million numbers? ...
Whenever I consider algorithms/data structures I tend to replace the log(N) parts by constants. Oh, I know log(N) diverges - but does it matter in real world applications? log(infinity) < 100 for all practical purposes. I am really curious for real world examples where this doesn't hold. To clarify: I understand O(f(N)) I am cu...
I know that some of the capabilities of the Perl regular expression engine are not regular. However, what class is it? It might be context-free, but CS theory was never my strongest subject. ...
A question in theory of Computer Science Today I can secretly store files in the cloud (say, amazon s3), by having them encrypted before I store them and decrypt them after I download. The storage provider cannot obtain any information from the stored files - everything is encrypted safely, and even symmetrical cipher will be ok here. ...
I think that the title accurately summarizes my question, but just to elaborate a bit, instead of using a regular expression to verify properties of existing strings, I'd like to use the regular expression as a way to generate strings that have certain properties. The function doesn't need to generate every string that satisfies the r...
Hi, I am studying coinduction(not induction) as part of a class on static analysis. Rummaging around the internet, I am simply not finding clear, concise description of: What coinduction is How coinduction actually proves something(it seems that coinduction is like waving a magic hand in the treatments I've read) What propositions req...
For my computer science class, we need to write a program (in C++) that takes an input of characters and outputs the possible permutations of it according to the dial pad on a phone, leaving non-digit characters in place. For example, inputing 2 outputs 2, A, B, C. Inputing 23 outputs 23, A3, B3, C3, 2D, 2E, 2F, AD, AE, AF, BD, BE, BF, ...
In Artificial Intelligence we studied the backtracking algorithm. Here is the pseudocode our book offers: function backtrack; begin SL:= [Start]; NSL := [Start]; DE := [] CS := Start; while NSL != [] do begin if CS = goal (or meets goal description) then return SL; if CS has no ch...
Since we have a thread on books.. what are your recommendations of publicly accessible video lecture series related to programming, computer science, or mathematics? Please post specific courses, not websites with courses. :) This is the video equivalent of this thread: http://stackoverflow.com/questions/194812/list-of-freely-available...
Is there a tool for examining the configuration and schema of a database for dubious fields, relationships and configuration, similar to how static analysis tools like lint will flag dubious lines of code? I'm not necessarily asking for normalization, but surely there's stupid stuff that can be detected without solving Hard AI or the Ha...
I haven't taken any math classes above basic college calculus. However, in the course of my programming work, I've picked up a lot of math and comp sci from blogs and reading, and I genuinely believe I have a decent mathematical mind. I enjoy and have success doing Project Euler, for example. I want to dive in and really start learning ...
Hi, As a programmer, I frequently need to be able to know the how to calculate the number of permutations of a set, usually for estimation purposes. There are a lot of different ways specify the allowable combinations, depending on the problem at hand. For example, given the set of letters A,B,C,D Assuming a 4 digit result, how m...
Hi everyone!!!!!!! What is a good book on Pi-calculus, which will give an idea of practical problems? Can you suggest some new technologies in Pi-calculus to learn? Thank you. ...
I have an assignment to write among other things, a set of prolog predicates that determine if any two binary tree's are isomorphic to each other. The predicate must also be able to provide all of the isomorphic graphs to any given binary tree. Here is what I have so far, it works except for returning duplicates. % Clause: btree_iso ...
If I have the input space of (1,2,....999). And I have a concept class C, with 10 concepts: C0,C1,C2...C9. Given an input, that input is an element of ci if the it contains the digit i. For example, the number 123 is an element of c1 and c2 and c3. What is the VC Dimension of this concept class C? ...
This is one of the tasks of my assignment. I have a Turing machine simulation which can simulate a busy beaver function. I have done some research about proving this problem, but still don't get it so I guess maybe you can help me here. A good source for me to go to or example of how to argue this would be good. ...
I have the following pseudo-code in my book for a breadth-first search: function breadth_first_search: begin open := [Start] closed := []; while open != [] do begin remove leftmost state from open, call it X; if X is a goal then return SUCCESS ...
Hello, I am searching for an online resource referring to data structures and algorithms. Basicaly what I am interested in, is a kind of comprehensive list of things such as: when a data structure or algorithm is used, pros and cons compared to each other, real life-problem usage, etc. I have a couple of popular books on the subject, l...