Efficient tree-traversals: reconciling parallelism and dense data representations

Recent work showed that compiling functional programs to use dense, serialized memory representations for recursive algebraic datatypes can yield significant constant-factor speedups for sequential programs. But serializing data in a maximally dense format consequently serializes the processing of that data, yielding a tension between density and parallelism. This paper shows that a disciplined, practical compromise is possible. We present Parallel Gibbon, a compiler that obtains the benefits of dense data formats and parallelism. We formalize the semantics of the parallel location calculus underpinning this novel implementation strategy, and show that it is type-safe. Parallel Gibbon exceeds the parallel performance of existing compilers for purely functional programs that use recursive algebraic datatypes, including, notably, abstract-syntax-tree traversals as in compilers.

An API in JAVA Which Render Ease at Programming for Developers

– Based on the concept of Application programming interface (API).This project comprises of a package named "algokit" which contains several algorithms based on the category of searching, sorting, dynamic programming, tree traversals and swapping. Keeping in mind that different algorithms from the same category have its own benefit in time and space complexity, This project covers almost all the algorithms known and available from each category. This would give the user several options to choose the right algorithm for its code.An user just requires to import the package named AlgoKit and call the functions inside it for a smooth programming experience. One of the prime objectives of this project is to build a kit that serves the purpose of reducing the number of lines of code and also reduce the time taken to run the same code elsewhere. It is platform independent and can be used in any open source Java development environment.

A Novel Encryption of Text Messages using Two Fold Approach

Background: The amount of digital data created and shared via internet has been increasing every day. The number of security threats has also increased due to the vulnerabilities present in the network hardware and software. Cryptography is the practice and study of techniques to secure communication in the presence of third parties. Though there are several cryptosystems to secure the information, there is a necessity to introduce new methods in order to protect information from the attackers. Objective: To propose a new encryption method using Binary Tree Traversal (BTT) and XOR operation to protect the text messages. Method: The proposed method uses both transposition and substitution techniques for converting plaintext into ciphertext. The notion binary tree traversal is adapted as transposition and bitwise XOR operation is used for substitution. Results: The repeating letters appeared in the plaintext are replaced with different cipher letters and placed on different location in the cipher text. Hence, it is infeasible to identify the plaintext message easily. The time taken by the proposed method for encryption is very less. Conclusion: A simple encryption method using binary tree traversals and XOR operation is developed. Encrypting data using binary tree traversals is a different way while compared with other traditional encryption methods. The proposed method is fast, secure and can be used to encrypt short messages in real time applications.

A Breadth-First, Ordered Parallel Tree Traversal

There has been a shift towards parallel computing in the computer science field over the past years, which has spurred interest in investigating the parallelization of classic sequential algorithms. Much research has been vested in graphs, particularly the application of breadth-first search. However, a subset of graphs, the tree data structure, has common use in various applications, yet focus tends to remain on graphs. A possible reason is that an effective graph algorithm could easily be applied to a tree, but a tree has a more distinct structure. Therefore, developing algorithms to exploit the specific design of a tree may improve efficiency over the application of a graph algorithm. We present concurrent breadth first tree traversal algorithm for M-ary trees, where M is an upper bound to the number of child nodes that a given node may have. The algorithm was developed in Java for portability and differs from other approaches in that it shall provide a meaningful ordering of nodes, which is absent in breadth first graph traversals. The approach provides relative fairness in the work done by each thread to aid scalability and eliminates the use of transactional memory, which appears in other concurrent tree traversals that do provide ordering. However, the use of rollback in these methods introduces a higher level of non-determinism to the computation, which we attempt to avoid for a better analysis of the algorithm.