用什么语言
C/C++如下
int main(){
int k=1;
double pi=0, sgn=1;
while(k<1000000)
{
pi+=sgn/k;
k+=2;
sgn=-sgn;
}
printf("%f\n",4. * pi);
return 0;
}
main()
{
int i;
double p=0.0;
for(i=1;i<=1000001;i+=2)
if(i%4==1)p+=1.0/i;
else p-=1.0/i;
printf("%.6f\n",4.0*p);
getch();
}