铠甲勇士地虎侠什么梗:用C语言画圆的一个问题！

一个C程序画圆，但是最后有一句提示，不知道为什么画不出来！请大鸟们帮忙指导！~

#include<stdio.h>
#include<graphics.h>
#include<dos.h>
void circlePoint(int xCenter, int yCenter,int x,int y)
{
putpixel(xCenter+x,yCenter +y,YELLOW);
putpixel(xCenter-x,yCenter+y,YELLOW);
putpixel(xCenter+x,yCenter-y,YELLOW);
putpixel(xCenter-x,yCenter-y,YELLOW);
putpixel(xCenter+y,yCenter+x,YELLOW);
putpixel(xCenter-y,yCenter+x,YELLOW);
putpixel(xCenter+y,yCenter-x,YELLOW);
putpixel(xCenter-y,yCenter-x,YELLOW);
}
void myCircle(int xCenter,int yCenter,int radius)
{
int x,y,p;
x=0;
y=radius;
p=1-radius;
circlePoint(xCenter,yCenter,x,y);
while(x<y){
x++;
if(p<0)
p+=2*x+1;
else
{y--;
p+=2*(x-y)+1;
}
circlePoint(xCenter ,yCenter,x,y);
}
}
void main()
{
int gdriver=DETECT,gmode;
int i;
int xCenter, yCenter,radius;
printf("Please input center coordinate:(x,y)");
scanf("%d,%d",&xCenter,&yCenter);
printf("please input radius:");
scanf("%d",&radius);
initgraph(&gdriver,&gmode,"c:\\turboc2\\bgi");
setcolor(BLUE);
myCircle(xCenter,yCenter,radius);
sleep(3);
closegraph();
return;
}

错误：BGI Error:Graphics not initialized (use 'initgraph')
这句英语是什么意思啊？谢谢帮助了！