python 使用二分法計算平方根
from math import sqrt
def mysqrt(num,small):
assert num>0
assert small>0
low = 0.0
high = max(num,1)
loops=1
while True and loops<=100:
a = (high + low) / 2
test = a ** 2
if abs(test-num)<small:
break
elif test > num:
high = a
else:
low = a
loops+=1
return a
if __name__ == '__main__':
num = input("number:")
small=0.0000000001
print mysqrt(num,small),"my sqrt " #對比我寫的這個和math庫的計算值的差別
print sqrt(num),"math sqrt"