Is Rabin Karp better than KMP?

The most important difference between them is how reliable they are in finding a match. KMP guarantees 100\% reliability. You cannot guarantee 100\% with Rabin Karp because of a chance of collision during hash table lookup.

What is the difference between naïve and Rabin-Karp string matching?

The Naive String Matching algorithm slides the pattern one by one. But unlike the Naive algorithm, Rabin Karp algorithm matches the hash value of the pattern with the hash value of current substring of text, and if the hash values match then only it starts matching individual characters.

How hash values are used in Rabin Karp algorithm and explain with an example?

The hash function suggested by Rabin and Karp calculates an integer value. The integer value for a string is the numeric value of a string. For example, if all possible characters are from 1 to 10, the numeric value of “122” will be 122.

Why is Rabin-Karp better than naive?

Like the Naive Algorithm, Rabin-Karp algorithm also slides the pattern one by one. But unlike the Naive algorithm, Rabin Karp algorithm matches the hash value of the pattern with the hash value of current substring of text, and if the hash values match then only it starts matching individual characters.

What is the KMP algorithm?

On the other hand, KMP generalizes nicely to the Aho-Corasick string-matching algorithm, which runs in time O (m + n + z), where z is the number of matches found and n is the combined length of the pattern strings. Notice that there’s no dependence here on the number of different pattern strings being searched for!

What is the difference between RK and KMP?

In KMP you might suffer some cache misses and branch misspredicts (especially with long patterns). In RK you need to do costly modulo operation. But most of the time KMP is faster.

Should I use KMP or Aho-Corasick?

When you want to search for multiple patterns, typically the correct choice is to use Aho-Corasick, which is somewhat a generalization of KMP. Now in your case you are only searching for 3 patterns so it may be the case that KMP is not that much slower (at most three times), but this is the general approach.

Does KMP have bad runtimes like Boyer-Moore?

Many Boyer-Moore implementations suffer from this second rule, but will not have bad runtimes in the first case. And KMP has no pathological worst-cases like these. One advantage of the Boyer-Moore algorithm is that it doesn’t necessarily have to scan all the characters of the input string.