Problem Detail: Given three strings $x$, $y$, and $z$ over an arbitrary finite alphabet, I need to determine their longest common subsequence (LCS). Example: A longest common subsequence of bandana, cabana, and magazine is aan. I’m trying to find an algorithm Read More …
Author: ignougroup
[Solved]: How can I analyze the time complexity of this Dynamic Time Warping algorithm implemented in MATLAB?
Problem Detail: I have a rough idea that the time complexity is O(mn) where m and n are based on the length of signals, as per this http://en.wikipedia.org/wiki/Dynamic_time_warping. How can I determine the time complexity of the following code (source) function Read More …
[Solved]: Complexity of the V-opt heuristic Traveling Salesman algorithm
Problem Detail: The paragraph on V-opt heuristic TSP algorithms at this site mentions a very effective algorithm due to Lin-Kernigham-Johnson. That page says: For many years Lin–Kernighan–Johnson had identified optimal solutions for all TSPs where an optimal solution was known and Read More …
[Solved]: Break an authentication protocol based on a pre-shared symmetric key
Problem Detail: Consider the following protocol, meant to authenticate $A$ (Alice) to $B$ (Bob) and vice versa. $$ begin{align*} A to B: &quad text{“I'm Alice”}, R_A B to A: &quad E(R_A, K) A to B: &quad E(langle R_A+1, P_Arangle, K) end{align*} Read More …
[Solved]: Making feature vector from Gabor filters for classification
Problem Detail: My aim is to classify types of cars (Sedans,SUV,Hatchbacks) and earlier I was using corner features for classification but it didn’t work out very well so now I am trying Gabor features. code from here Now the features are Read More …
[Solved]: What algorithms exist for solving natural number linear systems?
Problem Detail: I’m looking at the following problem: Given $n$-dimensional vectors of natural numbers $v_1, ldots, v_m$ and some input vector $u$, is $u$ a linear combination of the $v_i$’s with natural number coefficients? i.e. are there some $t_1, ldots, t_m Read More …
[Solved]: Job scheduling with a bottleneck problem
Problem Detail: Given $n$ jobs $J_1,J_2,…,J_n$, each job requires $T_i > 0, T_i in N$ time to complete. Each job must be pre-processed and post-processed by a single machine M that can handle only 1 job at a time and both Read More …
[Solved]: Are there established complexity classes with real numbers?
Problem Detail: A student recently asked me to check an NP-hardness proof for them. They performed a reduction along the lines of: I reduce this problem $P’$ that is known to be NP-complete to my problem $P$ (with a poly-time many-one Read More …
[Solved]: Is there any study or theory behind combining binary search and interpolation search?
Problem Detail: I just read Can this algorithm still be considered a Binary Search algorithm? and recalled that a few years back I wrote an indexer/search for log files to find log entries in large plain text files by date/time window. Read More …
[Solved]: Undergraduate Computer Science Textbooks
Problem Detail: What books would you recommend for someone starting B.Sc in Computer Science? My Personal Info: I am currently looking at B.Sc in Computer Science (Games), which is computer science, accept for the last year which is tailored more towards Read More …
