EULER MODIFIED METHOD USING C PROGRAM

#include<stdio.h>
#include<math.h>
float fun(float x,float y)
{
float f;
f=x*x+y;
return f;
}
int main()
{
float diff,y0,y,x0,x1,h,xn,y1,y2;
printf("enter x0,y0,h,xn\n");
scanf("%f%f%f%f",&x0,&y0,&h,&xn);
do
{
  y=y0+h*(fun(x0,y0));
  x1=x0+h;
  do
  {
  y2=y;
  y1=y0+(h/2)*(fun(x0,y0)+fun(x1,y));
  y=y1;
  diff=y1-y2;
  //printf("%f\n",y1-y2);
  }while(fabs(diff)>0.000001);
  y0=y1;
  x0=x0+h;
  printf("x=%f \t y=%f\n",x0,y1);
}while(x0<xn);
return 0;

}