most efficient way to check if a string is within a wordlist

Question

I need the most efficient way to determine whether a string is in a wordlist (this is a textfile of all words).

Obviously I could create an ofstream object and loop through each line to see whether the string is present.

Is there a quicker way? Perhaps by using a map?

Thanks

Answer 1

To find a particular word in a list of many words, I would use a std::unordered_set , which is a hash-table by another name.

Basically:

1. Read words from file into set.
2. Pick a "random combination of letters".
3. use find() to see if it's in the set.
4. Go to 2 as required.

Obviously, if you only want to search for a single word, it's no point in loading into a set. Just read the file and check as you go (because on average you'll only need to read half the file, which is obviously about 50% faster than reading the whole file)