Python 穷举法, 二分法 与牛顿-拉夫逊方法求解平方根的性能对比

穷举法, 二分法 与牛顿-拉夫逊方法求解平方根的优劣,从左到右依次递优。

经过测试,穷举法基本超过 1 分钟,还没有出数据;
二分法只要区区1秒不到就出结果了。
牛顿-拉夫逊是秒出,没有任何的停顿。

numberTarget =int(input("Please enter a number:"))
numberSqureRoot = 0
while(numberSqureRoot<abs(numberTarget)):
    if numberSqureRoot**2 >= abs(numberTarget):
        break
    numberSqureRoot = numberSqureRoot + 1

if numberSqureRoot**2 != numberTarget:
    print("Your number %s  is not  a perfect squre, the  square root is %s  " % ( numberTarget,numberSqureRoot) )
else:
    if numberTarget < 0 :
        numberSqureRoot = -numberSqureRoot
    print("Your number %s is   a perfect squre, the  square root is %s  " % ( numberTarget, numberSqureRoot))

print("now we begin to calculate the binary search...")

numberTarget=int(input("Please enter the number for binary search..."))
numberSqureRoot = 0

lowValue = 0.0
highValue=numberTarget*1.0

epsilon = 0.01
numberSqureRoot = (highValue + lowValue)/2

while abs(numberSqureRoot**2 - numberTarget) >=epsilon:
    print("lowValue:%s, highValue:%s, currentValue:%s"%(lowValue,highValue,numberSqureRoot))
    if numberSqureRoot**2<numberTarget:
        lowValue=numberSqureRoot
    else:
        highValue=numberSqureRoot
    numberSqureRoot = (lowValue+highValue) /2

print("The number %s has the squre root as %s " %(numberTarget,numberSqureRoot))


print("now we begin to calculate the newTon search...")

numberTarget=int(input("Please enter the number for newTon search..."))
numberSqureRoot = 0

epsilon = 0.01
k=numberTarget
numberSqureRoot = k/2.0

while( abs(numberSqureRoot*numberSqureRoot - k)>=epsilon):
    numberSqureRoot=numberSqureRoot-(((numberSqureRoot**2) - k)/(2*numberSqureRoot))

print("squre root of  %s is %s " %(numberTarget,numberSqureRoot))

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转载自blog.csdn.net/wujiandao/article/details/80232934