22 lines
737 B
Swift
22 lines
737 B
Swift
import Foundation
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func readInput(filePath: String) -> [[Int?]]? {
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let content = try? String(contentsOfFile: filePath, encoding: .ascii)
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let lines = content?.split(separator: "\n")
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return lines?.map { $0.split(separator: " ").map { Int($0) } }
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}
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func check(_ report: [Int?]) -> Bool? {
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if report.contains(nil) {
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return nil
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}
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let diffs = zip(report.dropFirst(), report).map { $0.0! - $0.1! }
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return diffs.allSatisfy { abs($0) >= 1 }
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&& diffs.allSatisfy { abs($0) <= 3 }
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&& (diffs.allSatisfy { $0 > 0 } || diffs.allSatisfy { 0 > $0 })
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}
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let reports = readInput(filePath: CommandLine.arguments[1])
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let answer = reports!.compactMap(check).reduce(0, {n, x in x ? n+1 : n})
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print(answer)
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