forming of powder
# include & ltstdio.h & gt

# include & ltmath.h & gt

Invalid? Master ()

{

Double? s=0,pi,t,d,c;

Double? I,n,j = 1; ? //It's all changed to double here.

for(i=2,n = 1; fabs( 1/n)>pow( 10,-6); i++,n++ = 2)

s=s+pow(- 1,I)* j/n; ? //Otherwise, this is the division of shaping, and the result will be rounded.

printf("%lf\n ",s); ? //Since s is a double, %lf should be used.

printf("pi=%lf\n ",pi = s * 4);

}