Your intuition behind why the algorithm should be Θ(n2) is a good one, but most suffix trees are designed in a way that eliminates the need for this time complexity. Intuitively, it would seem that you need Θ(n2) different nodes to hold all of the different suffixes, because you’d need n + (n – 1) … Read more
1) Concurrency. Do you have multiple people accessing the same dataset? Then it’s going to get pretty involved to broker all of the different readers and writers in a scalable fashion if you roll your own system. 2) Formatting and relationships: Is your data something that doesn’t fit neatly into a table structure? Long nucleotide … Read more
What you have coded in your example is very similar to a depth first search. So, that’s one answer. A depth first search algorithm without any special characteristics ( like re-convergent paths that can be optimized out ), should be n^n. This is actually not a contrived example. Chess programs operate on the same algorithm. … Read more
Data in an array can be rearranged into a heap, in place. The algorithm for this is actually surprisingly simple., but I won’t go into it here. For a heap sort, you arrange the data so that it forms a heap in place, with the smallest element at the back (std::make_heap). Then you swap the … Read more
Information on this topic is now available on Wikipedia at: Search data structure +———————-+———-+————+———-+————–+ | | Insert | Delete | Search | Space Usage | +———————-+———-+————+———-+————–+ | Unsorted array | O(1) | O(1) | O(n) | O(n) | | Value-indexed array | O(1) | O(1) | O(1) | O(n) | | Sorted array | O(n) … Read more
Testing is the best way to answer this question for your specific computer architecture, compiler, and implementation. Beyond that, there are generalizations. First off, priority queues are not necessarily O(n log n). If you have integer data, there are priority queues which work in O(1) time. Beucher and Meyer’s 1992 publication “The morphological approach to … Read more
It’s O(n). Consider this simple program: public class ArrayTest { public static void main(String[] args) { int[] var = new int[5]; } } The bytecode generated is: Compiled from “ArrayTest.java” public class ArrayTest extends java.lang.Object{ public ArrayTest(); Code: 0: aload_0 1: invokespecial #1; //Method java/lang/Object.”<init>”:()V 4: return public static void main(java.lang.String[]); Code: 0: iconst_5 1: … Read more
This really depends on the domain of what values you want to compute a logarithm of. For IEEE doubles, many processors can take logarithms in a single assembly instruction; x86 has the FYL2X and FYL2XP1 instructions, for example. Although typically instructions like these will only take the logarithm in some fixed base, they can be … Read more
It’s written in the documentation for Dictionary… The Dictionary generic class provides a mapping from a set of keys to a set of values. Each addition to the dictionary consists of a value and its associated key. Retrieving a value by using its key is very fast, close to O(1), because the Dictionary class is … Read more
The theoretical answers from everyone else are all neat, but let’s be pragmatic. ActionScript provides the tools you need so that you don’t even have to write a loop in this case! First, note that Math.min() and Math.max() can take any number of arguments. Also, it’s important to understand the apply() method available to Function … Read more