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--- Part Two ---
It turns out that this circuit is very timing-sensitive; you actually need to [1m[97mminimize the signal
delay[0m.
To do this, calculate the [1m[97mnumber of steps[0m each wire takes to reach each intersection; choose the
intersection where the [1m[97msum of both wires' steps[0m is lowest. If a wire visits a position on the grid
multiple times, use the steps value from the [1m[97mfirst[0m time it visits that position when calculating the
total value of a specific intersection.
The number of steps a wire takes is the total number of grid squares the wire has entered to get to
that location, including the intersection being considered. Again consider the example from above:
...........
.+-----+...
.|.....|...
.|..+--X-+.
.|..|..|.|.
.|.-X--+.|.
.|..|....|.
.|.......|.
.o-------+.
...........
In the above example, the intersection closest to the central port is reached after 8+5+5+2 =
[1m[97m20[0m steps by the first wire and 7+6+4+3 = [1m[97m20[0m steps by the second wire for a total of 20+20 =
[1m[97m40[0m steps.
However, the top-right intersection is better: the first wire takes only 8+5+2 = [1m[97m15[0m and the second
wire takes only 7+6+2 = [1m[97m15[0m, a total of 15+15 = [1m[97m30[0m steps.
Here are the best steps for the extra examples from above:
- R75,D30,R83,U83,L12,D49,R71,U7,L72
U62,R66,U55,R34,D71,R55,D58,R83 = 610 steps
- R98,U47,R26,D63,R33,U87,L62,D20,R33,U53,R51
U98,R91,D20,R16,D67,R40,U7,R15,U6,R7 = 410 steps
[1m[97mWhat is the fewest combined steps the wires must take to reach an intersection?[0m
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