float a;
driver=cga;mode=cgac0; initgraph(&driver,&mode,\
setcolor(3); setbkcolor(green); x0=150;y0=100; circle(x0,y0,10); circle(x0,y0,20); circle(x0,y0,50); for(i=0;i<16;i++)
{
a=(2*pai/16)*i; x=ceil(x0+48*cos(a)); y=ceil(y0+48*sin(a)*b); setcolor(2); line(x0,y0,x,y);} setcolor(3);circle(x0,y0,60); /* make 0 time normal size letters */ settextstyle(default_font,horiz_dir,0);
outtextxy(10,170,\
getch();
setfillstyle(hatch_fill,yellow);
floodfill(202,100,white);
getch(); for(k=0;k<=500;k++)
{
setcolor(3); for(i=0;i<=16;i++)
{
a=(2*pai/16)*i+(2*pai/180)*k;
x=ceil(x0+48*cos(a)); y=ceil(y0+48+sin(a)*b); setcolor(2); line(x0,y0,x,y);
}
for(j=1;j<=50;j++)
{
a=(2*pai/16)*i+(2*pai/180)*k-1;
x=ceil(x0+48*cos(a)); y=ceil(y0+48*sin(a)*b);
line(x0,y0,x,y);
} }
restorecrtmode();
}
==============================================================
【程序60】
题目：画图，综合例子。
1.程序分析： 2.程序源代码：
#include \ #define left 0 #define top 0 #define right 639 #define bottom 479 #define lines 400 #define maxcolor 15
main() {
int driver,mode,error;
int x1,y1; int x2,y2;
int dx1,dy1,dx2,dy2,i=1;
int count=0; int color=0; driver=vga; mode=vgahi;
initgraph(&driver,&mode,\
x1=x2=y1=y2=10; dx1=dy1=2; dx2=dy2=3; while(!kbhit())
{
line(x1,y1,x2,y2);
x1+=dx1;y1+=dy1; x2+=dx2;y2+dy2; if(x1<=left||x1>=right)
dx1=-dx1;
if(y1<=top||y1>=bottom)
dy1=-dy1; if(x2<=left||x2>=right)
dx2=-dx2; if(y2<=top||y2>=bottom)
dy2=-dy2; if(++count>lines)
{
setcolor(color);
color=(color>=maxcolor)0:++color;
} } closegraph();
} 【程序61】
题目：打印出杨辉三角形（要求打印出10行如下图）
1.程序分析： 1 1 1 1 2 1