#include "math.h"
  double ffts(a,b,eps,f)
  double a,b,eps,(*f)();
  { int n,k;
    double fa,fb,h,t1,p,s,x,t;
    fa=(*f)(a); fb=(*f)(b);
    n=1; h=b-a;
    t1=h*(fa+fb)/2.0;
    p=eps+1.0;
    while (p>=eps)
      { s=0.0;
        for (k=0;k<=n-1;k++)
          { x=a+(k+0.5)*h;
            s=s+(*f)(x);
          }
        t=(t1+h*s)/2.0;
        p=fabs(t1-t);
        t1=t; n=n+n; h=h/2.0;
      }
    return(t);
  }


#include "stdio.h"
  #include "9ffts.c"(w为以上函数文件名"9ffts.c"）
  main()
  { double a,b,eps,h,t1,t2,sum,fftsf(double);
    a=0.0; b=1.0; eps=0.000001;
    t1=ffts(a,b,eps,fftsf);
    a=1.0; b=2.0; eps=0.000001;
    t2=ffts(a,b,eps,fftsf);
   sum=t1+t2;
   printf("\n");
   printf("sum=%e\n",sum);
    printf("\n");
    return 0;
}

  #include "math.h"
  double fftsf(x)
  double x;
  { double y;
    y=(x*x);            （这里）
    return(y);
  }
当被积函数为y=x*x，结果为2.555556e+00
但被积函数为y=16.7*((2.0*(0.0003-0.5*x))/0.002-((0.0003-0.5*x)/0.002)*((0.0003-0.5*x)/0.002))怎么就不能算了呢？