36 lines
754 B
Swift
36 lines
754 B
Swift
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import Foundation
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let input = loadData(day: 25).lines().compactMap(Int.init)
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func loop(subject: Int, times: Int) -> Int {
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var value = 1
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for _ in 0..<times {
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value = (value * subject) % 20201227
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}
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return value
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}
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func findLoopSize(subject: Int, expected: Int) -> Int {
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var value = 1
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for i in 0...Int.max {
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if value == expected {
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return i
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}
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value = (value * subject) % 20201227
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}
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return -1
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}
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let sizes = input.map { findLoopSize(subject: 7, expected: $0) }
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print(sizes)
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let (pub1, pub2) = (input[0], input[1])
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let (loop1, loop2) = (sizes[0], sizes[1])
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let secret1 = loop(subject: pub2, times: loop1)
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let secret2 = loop(subject: pub1, times: loop2)
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print(secret1, secret2)
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