Over the next several videos we're 
going to design a program to solve Sudoku 
puzzles. 
So if you've never ever heard of Sudoku, 
you might want to take just a couple of 
minutes to do a Google search and go see 
a little bit of what the game's all 
about. 
But you don't need to get good at playing 
it, you just need to know the basic 
roles. 
Because our program isn't going to use 
human strategies for solving in the game. 
We're going to use something called Brute 
Force Search. 
And it's a wonderful insight. 
The insight basically is this. 
For some problems, what you can do is 
rather than come up with a kind of human 
strategy for playing it. 
You can generate the space of all 
possible solutions, and then just pick 
the best one. 
That's what's going to happen here. 
We're going to take a Sudoku board and 
we're going to generate a whole tree of 
all the possible boards that come after 
it. 
And then we'll just do a backtracking 
search over that to find the solution we 
want. 
Now two more things in terms in the way 
of intro. 
First, don't worry. 
We would never have expected you to come 
up with this idea of generating the 
search space at this point in the course. 
This was an idea that had to be invented 
quite some time ago. 
It, it's quite an interesting idea, so 
you wouldn't have to generate this idea. 
The amazing thing is once we layout this 
idea, what you're going to find is that 
you're all set to design this program. 
The rest of the week we're really only 
going to learn one more thing having to 
do with designing programs. 
In some sense, the rest of this is 
going to be a demonstration to you, by 
you, for you, of how much it is you 
already know how to do.