This is the first puzzle of this type which I created for practice of Indian Puzzle Team participating in World Puzzle Championship 2009. I have created some more puzzles of this type, which I will be posting here later.
This Puzzle type appeared in the following championships
"18th World Puzzle Championship, Antalya (Turkey)"
Paint some cells black to form a single closed loop that does not touch itself even at a point. Numbers in painted cells indicate the number of unpainted cells in neighbouring squares. Numbers in unpainted cells indicate the number of painted cells in neighbouring squares.