sqrt(x)和pow(x，0.5)之间的差异 [英] Difference between sqrt(x) and pow(x,0.5)

问题描述

我想知道为什么C/c ++中有sqrt()函数，因为我们可以使用

I was wondering why there is sqrt() function in C/c++ as we can achieve the same using

pow(x,0.5);

pow(x，0.5)的 sqrt(x)有何不同.有sqrt功能的特定原因吗?

how is sqrt(x) different for pow(x,0.5) . Is there a specific reason of having sqrt function?

推荐答案

我为您进行了一项测试，以检查 sqrt(x)和 pow(x，0.5)

I ran a test for you to check the performance of sqrt(x) and pow(x,0.5)

1.

for(int i=0;i<100000000;i++) 
    pow(double(i),0.5);

2.

for(int i=0;i<100000000;i++)
    sqrt(double(i));  

第一个人花了大约20秒，而第二个人花了大约2秒在我的计算机上.因此，性能会更好.正如其他人已经提到的，可读性是另一个原因.

1st one took around 20 seconds where as 2nd one took around 2 seconds on my computer. So performance is way better. As other have already mentioned readability is other reason.

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