题解 | #求解立方根#
求解立方根
https://www.nowcoder.com/practice/caf35ae421194a1090c22fe223357dca
num=float(input())
a=abs(num)
x1=0
x2=3
while True:
x=(x1+x2)/2
if abs(x**3-a)<=0.1:
if num<0:
print('{:.1f}'.format(float(-x)))
else:
print('{:.1f}'.format(float(x)))
break
elif x**3-a>0.1:
x2=x
else:
x1=x
