[wging]

If you want a few similar problems, in ascending order of difficulty, try #81 through #83:

https://projecteuler.net/problem=81

https://projecteuler.net/problem=82

https://projecteuler.net/problem=83

[Sohcahtoa82]

Couldn't all three of those be solved using the A* path-finding algorithm?

[wging]

Sshhh...