[_kst_]

"Test Your C Skills" is a published book by Yashavant Kanetkar, apparently published in 2005, and still available in paperback. The document you linked to appears to be a scan of a printed copy of that book, and is almost certainly in violation of copyright. The cover and the title and copyright pages are notably missing.

[Dylan16807]

That's worth being aware of, though somewhere around 20 years is where I start caring a lot less about copyright from a moral or practical point of view. Yeah, that book stays out of the public domain until the next century, but it shouldn't.

[vishnugupta]

> apparently published in 2005

No. It was published in late 90s. As per this copy on Archive.org 1997

https://archive.org/details/testyourcskills00yash