What is the best way of searching a word in file?

Hi, I’m developing a scrabble like game in which I want to check if the word created by user is available in file or not.

Please tell me the best and faster way of searching a word in file ?

And if possible with example.

Thanks.

This is really off topic for these forums. Plus, put in a little effort before just posting a question, please.

https://search.yahoo.com/yhs/search?p=searching+words+in+a+file+c%2B%2B&ei=UTF-8&hspart=mozilla&hsimp=yhs-002