19 lines
479 B
JavaScript
19 lines
479 B
JavaScript
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import fp from "lodash/fp.js";
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import u from "updeep";
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const update = (action, value) =>
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action === "down" ? u({ aim: fp.add(value) })
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: action === "up" ? u({ aim: fp.add(-value) })
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: u((state) =>
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u({ x: fp.add(value), depth: fp.add(value * state.aim) }, state)
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);
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export function solution(lines) {
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const { x, depth } = lines.reduce(
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(accum, line) => update(...line)(accum),
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{ depth: 0, aim: 0, x: 0 }
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);
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return x * depth;
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}
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