27 lines
416 B
Go
27 lines
416 B
Go
package main
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import (
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"fmt"
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)
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type ErrNegativeSqrt float64
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func (e ErrNegativeSqrt) Error() string {
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return fmt.Sprintf("cannot Sqrt negative number: %f", float64(e))
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}
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func Sqrt(x float64) (float64, error) {
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if x < 0 {
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return 0, ErrNegativeSqrt(x)
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}
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z := 1.0
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for count := 0; count < 10; count++ {
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z -= (z*z - x) / (2*z)
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}
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return z, nil
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}
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func main() {
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fmt.Println(Sqrt(2))
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fmt.Println(Sqrt(-2))
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}
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