Day 6: Guard Gallivant
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FAQ
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That’s about how long it takes for my python solution to complete.
How did you detect loops? I just ran for 100000 steps to see if I escaped, got my time down to 3s by doing only 10000 steps.
I added each visited position/direction to a set, and when a ‘state’ is reached again you have entered a loop:
v = set() while t[g.r][g.c] != 'X': state = (g.r, g.c, g.d) if state in v: acc += 1 break v.add(state) g.move(t)You can view my full solution here.
Not who you asked but: I save coordinates and direction into a vector each time the guard faces a #. Also every time the guard faces a #, I check if the position exists in the vector, if true, it’s an infinite loop. 78ms rust aolution.
That’s probably quite optimal, compared with checking every state in the path, or running off a fixed number of steps