# include & ltstdio.h & gt
Double factorial (integer)
{
return n & gt0 ? N * factorial (n-1):1;
}
Double power (int x, int y)
{
If (y>0)
return y & gt0 ? X * power (x, y-1):1;
other
return 1/(y & lt； 0 ? X * power (x, (-y)-1):1);
}
int main()
{
Double a = power (3,5); // 3^5
Double b = power (3,-5); // 3 ^-5
Double fac = factorial (10); // 10! = 10 * 9 * 8 *````* 2 * 1
printf(" 10！ = %lf\n "，fac)；
Printf("3 to the 5th power: %lf\n ",a);
Printf("3 to the fifth power: %lf\n ",b);
}
There is no symbol defining factorial in the computer, but an exclamation point in mathematics, such as 5! Equal to 5 * 4 * 3 * 2 * 1, so equal to 120.