怎么编一个c语言程序算两点间距离，答案保留两位小数

怎么编一个c语言程序算两点间距离，答案保留两位小数

#include
#include
double distance(double x0,double y0,double x1,double y1) { double d,x,y;
x=x0-x1; y=y0-y1; x*=x; y*=y; x+=y; d=sqrt(x); return d;
}
void main() { double x0,x1,y0,y1,d;
scanf("%lf%lf%lf%lf",&x0,&y0,&x1,&y1);
d=distance(x0,y0,x1,y1);
printf("%.2lf\n",d);
}

float a,c; int b; a=1.1; b=100; c=a*(float)b; printf("%.2f",c);