Problem Detail: I am new to CFG’s, Can someone give me tips in creating CFG that generates some language For example $L ={ w v w^R mid v,win {a,b}^*wedge|v| text{ is even } }$, where $w^R$ is the reverse of string Read More …
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[Solved]: Approximation algorithm for Feedback Arc Set
Problem Detail: Given a directed graph $G = (V,A)$, a feedback arc set is a set of arcs whose removal leaves an acyclic graph. The problem is to find the minimum cardinality such set. I want to find out about is Read More …
[Solved]: What is a malformed token?
Problem Detail: I am reading Programming Language Pragmatics by Michael Scott. He says that on a first pass, a compiler will break a program into a series of tokens. He says that it will check for malformed tokens, like 123abc or Read More …
[Solved]: Sum of all nodes from A to B in a Tree
Problem Detail: Given a Tree and pointers to two of it’s nodes A and B (a key value of each node is positive). Find an algorithm that sums up all the values on the path between A and B, when preproccessing Read More …
[Solved]: Is it possible to create a “Time Capsule” using encryption?
Problem Detail: I want to create a digital time capsule which will remain unreadable for some period of time and then become readable. I do not want to rely on any outside service to, for instance, keep the key secret and Read More …
[Solved]: Where/when did Stephen Kleene first define the Kleene closure/star?
Problem Detail: I’m working on a paper and would like to review the origins of Kleene’s closure. I am unable to find any article of Kleene’s that has the original definition of the Kleene closure. Is there a paper by Kleene Read More …
[Solved]: Shortest path from starting cell to all cells in the grid
Problem Detail: I found an algorithm for finding the shortest path on grid between selected cell, to all cells on the grid, with $O(KN)$ where $K$ is the number of neighbor cells and $N$ is the number of cells. How ever Read More …
[Solved]: Regarding to the speed of supercomputer
Problem Detail: There seems to be a sense of competition in creating the fastest computer in the world, and I feel like technically you just have to continue increasing the core number to gain more flops, which is exactly what some Read More …
[Solved]: Why does TSP require no repetition of cities?
Problem Detail: It seems odd to me that the TSP denies the possibility of repeated cities. The goal of this traveling salesman is to go as fast as possible and visit all of the cities, right? So what if it is Read More …
[Solved]: Finding median of three sorted array (the same length)
Problem Detail: I think about following problem: There are given three sorted arrays $A,B,C$ (each of them is length $n$). Every array has distinct elements. Find median of union $A,B,C$. I consider following approach: Let’s consider $A_i, B_i, C_i$, where $i=n/2$. Read More …
