题目：

题解：

func myPow(x float64, n int) float64 {if n >= 0 {return quickMul(x, n)}return 1.0 / quickMul(x, -n)
}func quickMul(x float64, n int) float64 {if n == 0 {return 1}y := quickMul(x, n/2)if n%2 == 0 {return y * y}return y * y * x
}