Python基于二分查找实现求整数平方根的方法

x=int(raw_input('please input a int:'))if x<0:   retrun -1low=0high=xans=(low+high)/2.0sign=answhile ans**2 !=x:  if ans**2>x:    high=ans  else:    low=ans  ans=(low+high)/2.0  if sign==ans:    breakprint ans