Bellman-Ford algorithm is a single-source shortest path algorithm, so when you have negative edge weight then it can detect negative cycles in a graph. The only difference between the two is that Bellman-Ford is also capable of handling negative weights whereas Dijkstra Algorithm can only handle positives. From wiki However, Dijkstra’s algorithm greedily selects the … Read more
Usually nowadays I see It used to be common to see It all gets the point across.
I’m programming a spellcheck program in Python. I have a list of valid words (the dictionary) and I need to output a list of words from this dictionary that have an edit distance of 2 from a given invalid word. I know I need to start by generating a list with an edit distance of … Read more
n log(n) implies that the algorithm looks at all N items log(n) times. But that’s not what’s happening with Quickselect. Let’s say you’re using Quickselect to pick the top 8 items in a list of 128. And by some miracle of random selection, the pivots you pick are always at the halfway point. On the … Read more
O( log* N ) is “iterated logarithm“: In computer science, the iterated logarithm of n, written log* n (usually read “log star”), is the number of times the logarithm function must be iteratively applied before the result is less than or equal to 1.
Just ask wolframalpha if you have doubts. In this case, it says Or you can also calculate the limit yourself: That means n^2 grows faster, so n log(n) is smaller (better), when n is high enough.
Knuth’s multiplicative method: In general, you should pick a multiplier that is in the order of your hash size (2^32 in the example) and has no common factors with it. This way the hash function covers all your hash space uniformly. Edit: The biggest disadvantage of this hash function is that it preserves divisibility, so if … Read more
An algorithm is the description of an automated solution to a problem. What the algorithm does is precisely defined. The solution could or could not be the best possible one but you know from the start what kind of result you will get. You implement the algorithm using some programming language to get (a part of) a program. Now, … Read more
Hash tables are O(1) average and amortized case complexity, however it suffers from O(n) worst case time complexity. [And I think this is where your confusion is] Hash tables suffer from O(n) worst time complexity due to two reasons: If too many elements were hashed into the same key: looking inside this key may take O(n) time. Once a hash table has passed its load balance – it has … Read more
This may help: To put it simple, ADT is a logical description and data structure is concrete. ADT is the logical picture of the data and the operations to manipulate the component elements of the data. Data structure is the actual representation of the data during the implementation and the algorithms to manipulate the data … Read more