题解 | #正则匹配#
求解立方根
http://www.nowcoder.com/practice/caf35ae421194a1090c22fe223357dca
for line in sys.stdin:
n=float(line.strip())
last=n
new=last-((last**3-n)/(3*last**2))
while abs(new-last)>0.000001:#精度要求
last=new
new=last-((last**3-n)/(3*last**2))
print(format(new,'.1f'))
