Question

用C语言的递归方法求1!+3!+5!+7!

Answer 1

int
work(int
x,
int
&sum)
{
int
y;

if
(x<=1)
{sum+=1;return
1;}

y=work(x-1,sum)*x;

if
(x%2)
sum+=y;

return
y;
}
void
main()
{int
sum;
work(7,sum);
printf("%d",sum)}
/////////////////
正好以前写过
fs(n)当洞搜n为偶数时求2!+4!+...+n!
奇数是是旁桐求1!+3!+5!...+n!
//
S:~
#include
<stdio.h>
double
_fs(double
x,
double
y)
{

return
y
>=
3
?
_fs(((x
==
y
?
x*(x-1)
:
x)+1)*(y-2)*(y-3
==
0
?
1
:
y-3),
y-2)
:
x;
}
#define
fs(a)
_fs(a,
a)
int
main()
{

printf("%g"纳启历,
fs(7));

return
0;
}