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Josh Creek
28 lines
1.4 KiB
Plaintext
28 lines
1.4 KiB
Plaintext
--- Part Two ---
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It turns out that this circuit is very timing-sensitive; you actually need to minimize the signal delay.
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To do this, calculate the number of steps each wire takes to reach each intersection; choose the intersection where the sum of both wires' steps is lowest. If a wire visits a position on the grid multiple times, use the steps value from the first time it visits that position when calculating the total value of a specific intersection.
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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:
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...........
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.+-----+...
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.|.....|...
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.|..+--X-+.
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.|..|..|.|.
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.|.-X--+.|.
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.|..|....|.
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.|.......|.
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.o-------+.
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...........
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In the above example, the intersection closest to the central port is reached after 8+5+5+2 = 20 steps by the first wire and 7+6+4+3 = 20 steps by the second wire for a total of 20+20 = 40 steps.
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However, the top-right intersection is better: the first wire takes only 8+5+2 = 15 and the second wire takes only 7+6+2 = 15, a total of 15+15 = 30 steps.
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Here are the best steps for the extra examples from above:
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R75,D30,R83,U83,L12,D49,R71,U7,L72
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U62,R66,U55,R34,D71,R55,D58,R83 = 610 steps
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R98,U47,R26,D63,R33,U87,L62,D20,R33,U53,R51
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U98,R91,D20,R16,D67,R40,U7,R15,U6,R7 = 410 steps
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What is the fewest combined steps the wires must take to reach an intersection? |