Solve 'simple' chess puzzle to win one million dollars

Building a computer programme to solve a chess problem called the Queens Puzzle could win you a prize of million dollars, say scientists who have thrown open a challenge that they claim is impossible to crack.
Devised in 1850, the Queens Puzzle originally challenged a player to place eight queens on a standard chessboard so that no two queens could attack each other.
This means putting one queen in each row, so that no two queens are in the same column, and no two queens are in the same diagonal.
Although the problem has been solved by human beings, once the chess board increases to a large size no computer programme can solve it.

Researchers from the University of St Andrews in the UK believe any programme that can crack the famous "Queens Puzzle", would be so powerful that it could solve tasks currently considered impossible, such as decrypting the toughest security on the internet.
They found that once the chess board reached 1,000 by 1,000 squares, computer programmes could no longer cope with the vast number of options and sunk into a potentially eternal struggle.

The struggle is akin to the fictional "super computer" Deep Thought in Douglas Adams' popular sci-fi series the Hitchhiker's Guide to the Galaxy, which took seven and a half million years to provide an answer to the 'Meaning of Everything', researchers said.

"If you could write a computer programme that could solve the problem really fast, you could adapt it to solve many of the most important problems that affect us all daily," said Ian Gent, professor at St Andrews.
"This includes trivial challenges like working out the largest group of your Facebook friends who do not know each other, or very important ones like cracking the codes that keep all our online transactions safe," Gent added.
The reason these problems are so difficult for computer programmes, is that there are so many options to consider that it can take many years, researchers said.

This is due to a process of "backtracking" - an algorithm used in programming where every possible option is considered and then "backed away" from until the correct solution is found, they said.
"However, this is all theoretical, in practise, nobody has ever come close to writing a programme that can solve the problem quickly. So what our research has shown is that - for all practical purposes - it can not be done," said Peter Nightingale, a senior research fellow at St Andrews.
The prize money of one million USD, awarded by Clay Mathematics Institute in the US is available to anyone who can solve the puzzle.

The study was published today in the Journal of Artificial Intelligence Research.