SE250:lab-X:gfun006
Task 1
There are 9 possible spaces to put in "1 2 3 4 5 6 7 8 X" where X is the empty space. Thus in the first space there are 9 different possibilities, then 8, then 7 etc, ending up with 9 x 8 x 7 x 6 x 5 x 4 x 3 x 2 x 1 = 9! = 362880. The number of edges is I estimated was (4 x 8! + 3x4 x 8! + 2x4 x 8!)/2. That is a pure estimate, but I got that answer because I figured that when the state has a empty space in the middle, there are 4 different ways to move, when they are on the corners, there are 2 different ways and on the sides there are 3 different ways. There can only be one instance when the empty space is in the middle, 4 instances for the corner and 4 for the sides. Also, there is always the possibility of a state returning backwards, thus the answer is divided by 2.
Task 2
STACK
Task 3
1 2 3
4 5 6
7 8
1 2 3 1 2 3
5 6 4 5 6
4 7 8 7 8
1 2 3 2 3 1 2 3 1 2 3
5 6 1 5 6 4 6 4 5 6
4 7 8 4 7 8 7 5 8 7 8
There is always also the possibility of making a move back to the parent state every time. Spent a lot of time figuring out how cygwin works and then had to change the dot command again. It was not fun.
Task 4
For some reason my search.c kept printing 10714 nodes. I don't know why.
Oh right, I'm an idiot and forgot to change the start and goal. I changed start to "123456.78" and goal to "12345678.". This gave me the output of: <HTML>
123 456 .78 123 456 7.8 123 456 78. 123 456 .78 -> 123 456 7.8 -> 123 456 78. -> Visited 5 states
</HTML>
I put the print_state(&s) command after the pop_OrderedStateList( &open, &s ) command. The output seems to make sense...although I don't understand why it visited 5 states. It seemed to only go through 3.