Evaluate math expressions without a stack

How do you evaluate arbitrary math expressions using temporary variables instead of a stack? What I’m talking about is translating an expression into an array of simple operations- each that change one variable based on the second argument.

What are the differences between algorithms using data structures and algorithms using databases?

The General Question What are the differences between algorithms using data structures and algorithms using databases? Some Context This is a question that has been bugging me for some time, and I have not been able to come up with a convincing answer for it. Currently, I am working on strengthening my understanding of algorithms […]

Root cause analysis in event correlation

I’m to write an event correlator module for the device we produce. When a fault occurs the resulting avalanche of logs about derivative conditions from various modules is readable only to a person skilled in the task – a layman will be utterly lost. The event correlator is supposed to solve this problem – find root cause and present a friendly message guiding the user to the origin of the problem.

Versioned Resources to Improve Cacheability

Here’s an API concept which could be useful for performance optimisation. It’s an example of key-based cache expiry applied to a broader internet-wide context instead of the internal Memcached-style scenario it seems to be mostly used for.

Is this XOR value swap algorithm still in use or useful

When I first started working a mainframe assembler programmer showed me how they swap two values without using the traditional algorithm of:

Which k-best shortest-path algorithms should I consider?

I’m solving a graph-search optimization problem. I need to find the k best acyclic shortest-paths through a directed weighted graph.

Compress range of numbers into blocks of used or unused

Given a numerical range and a list of used numbers that fall within that range I need to compress the range into blocks of used and unused numbers.

Pattern for mobile app data synchronisation using HTTP over 3G networks

I have a mobile app built using jquerymobile, PhoneGap and some custom CSS and JavaScript. The data objects are received in JSON and used to display different forms to the user. For example

Loop invariant vs Assertions

I have an exam on Programming Concepts this Saturday and I am struggling to find some information to understand some concepts better.

find second smallest element in Fibonacci Heap

I need to describe an algorithm that finds the second smallest element in a Fibonacci-Heap using the Operations: Insert, ExtractMin, DecreaseKey and GetMin. The last one is an algorithm previously implemented to find and return the smallest element of the heap.