22 lines
521 B
Swift
22 lines
521 B
Swift
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struct SplitMix64 : RandomNumberGenerator {
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public typealias State = UInt64
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public private(set) var state: State
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init(state: UInt64) {
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self.state = state
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}
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public mutating func next() -> UInt64 {
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state &+= 0x9E3779B97F4A7C15
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var z = state
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z = (z ^ (z >> 30)) &* 0xBF58476D1CE4E5B9
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z = (z ^ (z >> 27)) &* 0x94D049BB133111EB
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return z ^ (z >> 31)
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}
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public mutating func nextDouble() -> Double {
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Double(next() >> 11) * 0x1.0p-53
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}
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}
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