阶乘 -C (Linux)
请建议我一个更有效的替代方案来执行此计划
#include <stdio.h>
int main(void)
{
int k, i, t;
int arr[100]; //Declaring an array
printf("Enter a positive integer: ");
scanf("%d", &k);
for (i = 0; i < k; i++)
{
//printf("enter a value %d : ", i);
scanf("%d", &arr[i]);
}
for (i = 0; i < k; i++)
{
fact(arr[i]);
}
}
int fact(int num) // defining function fact(Num)
{
int i;
int fact1 = 1;
for (i = 1; i <= num; i++)
{
fact1 = fact1 * i;
}
printf("%ld\n", fact1);
}
Please suggest me a more efficient alternative to go about this Program
#include <stdio.h>
int main(void)
{
int k, i, t;
int arr[100]; //Declaring an array
printf("Enter a positive integer: ");
scanf("%d", &k);
for (i = 0; i < k; i++)
{
//printf("enter a value %d : ", i);
scanf("%d", &arr[i]);
}
for (i = 0; i < k; i++)
{
fact(arr[i]);
}
}
int fact(int num) // defining function fact(Num)
{
int i;
int fact1 = 1;
for (i = 1; i <= num; i++)
{
fact1 = fact1 * i;
}
printf("%ld\n", fact1);
}
如果你对这篇内容有疑问，欢迎到本站社区发帖提问 参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。
绑定邮箱获取回复消息
由于您还没有绑定你的真实邮箱，如果其他用户或者作者回复了您的评论，将不能在第一时间通知您！
发布评论
评论（4）
对于小争论，我同意 Hamish Grubijan 的评论：只需将值制成表格并在运行时查找即可。 n! 的值并不多。以机器编号表示，因此您可以将它们全部制成表格。
n! 的对数通常更有用。当 n! 时，它将适合机器编号。本身就会溢出。请参阅如何计算对数阶乘 。
For small arguments, I agree with Hamish Grubijan's comment: just tabulate the values and look 'em up at run time. There aren't that many values for which n! is representable in a machine number, so you could tabulate them all.
The logarithm of n! is often more useful. It will fit inside a machine number when n! itself would overflow. See How to compute log factorial.
您可以使用斯特林公式作为大阶乘的近似值。如果需要非常大的精确阶乘，则需要使用 bignum 算术。渐进最佳效率是通过计算 n! 获得的。从它的质因数分解。如需了解更多算法，请查看此
You can use Stirling's formula as an approximation for large factorials. If very large exact factorials are needed, you'll need to use bignum arithmetic. The asymptotically-best efficiency is obtained by computing n! from its prime factorization. For more algorithms, check this
您可以使用斯特林近似来计算大数的阶乘。
You can use Stirling's approximation to calculate the factorial for large numbers.
请参阅快速阶乘函数网站和部分“nofollow noreferrer">阶乘 维基百科文章。
See the Fast Factorial Functions website and to the Computation section of the Factorial Wikipedia article.