Day 6: Guard Gallivant

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FAQ

  • CameronDev@programming.devOPM
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    9 days ago

    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.

    • Leavingoldhabits@lemmy.world
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      9 days ago

      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.

      • CameronDev@programming.devOPM
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        9 days ago

        That’s probably quite optimal, compared with checking every state in the path, or running off a fixed number of steps

    • TunaCowboy@lemmy.world
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      9 days ago

      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.