要求使用c或c++编写用Bresenham算法生成逆时针方向的位于第一象限的一段圆弧的算法

#include<graphics.h>
#include<stdio.h>
#include<conio.h>   
#include<math.h>
void circlepoint(int x,int y,int color)
{
    putpixel(y+200,-x+200,color);
    putpixel(x+200,-y+200,color);
}
void midbresenhamcircle(int r,int color)
{
    int x,y,d;
    x=0;y=r;d=1-r;
    while(x<=y)
    {
        circlepoint(x,y,color);
        if(d<0)
        d+=2*x+3;
        else
        {
            d+=2*(x-y)+5;
            y--;
        }
        x++;
    }
}
void main()
{
    int gd,gm;
    int r;
    gd=DETECT;
    initgraph(&gd,&gm,"e:\tc2.0");
    printf("please input circle r:");
    scanf("%d",&r);
    midbresenhamcircle(r,2);
    getch();
    closegraph();
}