47 lines
1.2 KiB
Go
47 lines
1.2 KiB
Go
// Go's `math/rand` package provides
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// [pseudorandom number](http://en.wikipedia.org/wiki/Pseudorandom_number_generator)
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// generation.
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package main
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import "fmt"
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import "math/rand"
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func main() {
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// For example, `rand.Intn` returns a random `int` n,
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// `0 <= n < 100`.
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fmt.Print(rand.Intn(100), ",")
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fmt.Print(rand.Intn(100))
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fmt.Println()
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// `rand.Float64` returns a `float64` `f`,
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// `0.0 <= f < 1.0`.
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fmt.Println(rand.Float64())
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// This can be used to generate random floats in
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// other ranges, for example `5.0 <= f' < 10.0`.
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fmt.Print((rand.Float64()*5)+5, ",")
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fmt.Print((rand.Float64() * 5) + 5)
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fmt.Println()
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// To make the pseudorandom generator deterministic,
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// give it a well-known seed.
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s1 := rand.NewSource(42)
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r1 := rand.New(s1)
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// Call the resulting `rand.Source` just like the
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// functions on the `rand` package.
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fmt.Print(r1.Intn(100), ",")
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fmt.Print(r1.Intn(100))
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fmt.Println()
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// If you seed a source with the same number, it
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// produces the same sequence of random numbers.
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s2 := rand.NewSource(42)
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r2 := rand.New(s2)
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fmt.Print(r2.Intn(100), ",")
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fmt.Print(r2.Intn(100))
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fmt.Println()
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}
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