Did I accidentally root? Why is my LG G2 broken?

[AC Question]

So about 2-3 weeks ago I went into software information and I was spamming the android version to get the cool android jelly bean thing right? And then I went back and for some reason just started spamming the other buttons there including the build number, (without knowing then that it was the button to turn on developer option.) Anyway I didn't notice anything different but my friend said that I rooted my phone? Do I still have my warranty? When I go to dropbox it says I have a folder named "root." But I don't think that rooting my phone would be this easy. Anyways a few days ago there was a software update, a small one, and I did it properly, and it was fine, when yesterday my phone while I was on snapchat just froze and then turned off and wouldn't turn on again for like 10 minutes. Now it just randomly turns off, 5 times today so far. If it's the phone messing up, can I still return it? Please help, thanks.

 

[Minchan Han]

This was me by the way forgot to sign in