136.绘制正多边形

  

   

    

     

    
    

     

      #include <graphics.h>
     
    
   

    

     

    
    

     

      #include <math.h>
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      void polygon(x0,y0,a,n,af)
     
    
   

    

     

    
    

     

      int x0,y0,a,n;
     
    
   

    

     

    
    

     

      float af;
     
    
   

    

     

    
    

     

      {
     
    
   

    

     

    
    

     
	int x,y,i;
     
    
   

    

     

    
    

     
	float dtheta,theta;
     
    
   

    

     

    
    

     
	if(n<3)
     
    
   

    

     

    
    

     
		return;
     
    
   

    

     

    
    

     

      	dtheta=6.28318/n;
     
    
   

    

     

    
    

     

      	theta=af*0.0174533;
     
    
   

    

     

    
    

     
	moveto(x0,y0);
     
    
   

    

     

    
    

     

      	x=x0;
     
    
   

    

     

    
    

     

      	y=y0;
     
    
   

    

     

    
    

     
	for(i=0;i<n;i++)
     
    
   

    

     

    
    

     

      	{
     
    
   

    

     

    
    

     

      		x=x+a*cos(theta);
     
    
   

    

     

    
    

     

      		y=y+a*sin(theta);
     
    
   

    

     

    
    

     
		lineto(x,y);
     
    
   

    

     

    
    

     

      		theta=theta+dtheta;
     
    
   

    

     

    
    

     

      	}
     
    
   

    

     

    
    

     
	lineto(x0,y0);
     
    
   

    

     

    
    

     

      }
     
    
   

    

     

    
    

     

      void main()
     
    
   

    

     

    
    

     

      {
     
    
   

    

     

    
    

     
	int i,a=80,x=200,y=100;
     
    
   

    

     

    
    

     
	int gdriver=DETECT,gmode;
     
    
   

    

     

    
    

     
	initgraph(&gdriver,&gmode,"C:\\tc");
     
    
   

    

     

    
    

     
	cleardevice();
     
    
   

    

     

    
    

     
	setbkcolor(9);
     
    
   

    

     

    
    

     
	setcolor(4);
     
    
   

    

     

    
    

     
	for(i=3;i<=10;i++)
     
    
   

    

     

    
    

     
		polygon(x,y,a,i,0.);
     
    
   

    

     

    
    

     
	getch();
     
    
   

    

     

    
    

     
	closegraph();
     
    
   

    

     

    
    

     

      }
     
    
  
 

文章来源: blog.csdn.net，作者：程序员编程指南，版权归原作者所有，如需转载，请联系作者。

原文链接：blog.csdn.net/weixin_41055260/article/details/124665221