There's a site called Array Overflow at https://arrayoverflow.com. Is it legit? Its Facebook Page says nothing about the operator of the web site, and at the bottom of the site it just says (C) Array Overflow.
No, this is not a Stack Exchange site. You can find almost all sites here. There are a few more "secret" ones. But this isn't one of them.
Besides that there is only a limited set of domains used by Stack Exchange. Most sites are hosted as subdomains of stackexchange.com. Exceptions are the original trilogy sites: StackOverflow.com, SuperUser.com and ServerFault.com. Besides those three there are MathOverflow.net and AskUbuntu.com and the special case of Stackapps.com
As far as the questions go, I googled some of them, and none appear to be copied from Stack Overflow, or any other SE site. They do however show some strong resemblance to other sites, but that is not something Stack Exchange has any business with.
They however certainly do their best to look like an Stack Exchange site, and hope to profit of the Stack Exchange / Stack Overflow name I guess. If you for example look at the tabs on your browser they bear a lot of resemblance: