The most efficient way to search for an array of strings in another string

Question

I have a large arrray of strings that looks something like this: String temp[] = new String[200000].

I have another String, let\'s call it bigtext. What I ne

Answer 1

Note that your current complexity is O(|S1|*n), where |S1| is the length of bigtext and n is the number of elements in your array, since each search is actually O(|S1|).

By building a suffix tree from bigtext, and iterating on elements in the array, you could bring this complexity down to O(|S1| + |S2|*n), where |S2| is the length of the longest string in the array. Assuming |S2| << |S1|, it could be much faster!

Building a suffix tree is O(|S1|), and each search is O(|S2|). You don't have to go through bigtext to find it, just on the relevant piece of the suffix tree. Since it is done n times, you get total of O(|S1| + n*|S2|), which is asymptotically better then the naive implementation.