题解 | #求解立方根#

package main

import (
	"fmt"
)

func main() {
	var input float64
	var result float64
	fmt.Scan(&input)
	sign := true
	if input < 0 {
		sign = false
		input = -input
	}
	internal := 0.001

	for i := float64(0); i < 3; i += internal {
		i0 := i*i*i - input
		i1 := (i+internal)*(i+internal)*(i+internal) - input
		if i0*i1 < 0 {
			if i0-input > 0 {
				result = i0 + internal
			} else {
				result = i
			}
			break
		}
	}

	if !sign {
		result = -result
	}

	fmt.Printf("%.1f", result)
}