Kangaroo problem, np complete :)

[SCM]

Lanzaa asked

Code:

Btw how long is the bridge?

In Agamemnus' description of the problem he wrote

Code:

'At first the kangaroos line up like this: >>>_<<< (n = 3)
'They need to line up like this:           <<<_>>>

Think of the bridge as being 2*n+1 spaces long. Since there are 2*n kangaroos, there is always one free space to move into by either a

Code:

>>_<<      (n=2)
    hop    >_><<

or a

Code:

>_><<      
    jump   ><>_<