C语言经典算法59-66

【程序59】
题目：画图，综合例子。
1.程序分析：
2.程序源代码：
# define PAI 3.1415926
# define B 0.809
# include "graphics.h"
#include "math.h"
main()
{
int i,j,k,x0,y0,x,y,driver,mode;
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,"press a key");
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 "graphics.h"
#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
1 3 3 1
1 4 6 4 1
1 5 10 10 5 1
2.程序源代码：
main()
{int i,j;
int a[10][10];
printf("n");
for(i=0;i<10;i++)
{a[0]=1;
a=1;}
for(i=2;i<10;i++)
for(j=1;j a[j]=a[i-1][j-1]+a[i-1][j];
for(i=0;i<10;i++)
{for(j=0;j<=i;j++)
printf("]",a[j]);
printf("n");
}
}
==============================================================
【程序62】
题目：学习putpixel画点。
1.程序分析：
2.程序源代码：
#include "stdio.h"
#include "graphics.h"
main()
{
int i,j,driver=VGA,mode=VGAHI;
initgraph(&driver,&mode,"");
setbkcolor(YELLOW);
for(i=50;i<=230;i+=20)
for(j=50;j<=230;j++)
putpixel(i,j,1);
for(j=50;j<=230;j+=20)
for(i=50;i<=230;i++)
putpixel(i,j,1);
}
==============================================================
【程序63】
题目：画椭圆ellipse
1.程序分析：
2.程序源代码：
#include "stdio.h"
#include "graphics.h"
#include "conio.h"
main()
{
int x=360,y=160,driver=VGA,mode=VGAHI;
int num=20,i;
int top,bottom;
initgraph(&driver,&mode,"");
top=y-30;
bottom=y-30;
for(i=0;i{
ellipse(250,250,0,360,top,bottom);
top-=5;
bottom+=5;
}
getch();
}
==============================================================
【程序64】
题目：利用ellipse and rectangle 画图。
1.程序分析：
2.程序源代码：
#include "stdio.h"
#include "graphics.h"
#include "conio.h"
main()
{
int driver=VGA,mode=VGAHI;
int i,num=15,top=50;
int left=20,right=50;
initgraph(&driver,&mode,"");
for(i=0;i{
ellipse(250,250,0,360,right,left);
ellipse(250,250,0,360,20,top);
rectangle(20-2*i,20-2*i,10*(i+2),10*(i+2));
right+=5;
left+=5;
top+=10;
}
getch();
}
==============================================================
【程序65】
题目：一个最优美的图案。
1.程序分析：
2.程序源代码：
#include "graphics.h"
#include "math.h"
#include "dos.h"
#include "conio.h"
#include "stdlib.h"
#include "stdio.h"
#include "stdarg.h"
#define MAXPTS 15
#define PI 3.1415926
struct PTS {
int x,y;
};
double AspectRatio=0.85;
void LineToDemo(void)
{
struct viewporttype vp;
struct PTS points[MAXPTS];
int i, j, h, w, xcenter, ycenter;
int radius, angle, step;
double rads;
printf(" MoveTo / LineTo Demonstration" );
getviewsettings( &vp );
h = vp.bottom - vp.top;
w = vp.right - vp.left;
xcenter = w / 2; /* Determine the center of circle */
ycenter = h / 2;
radius = (h - 30) / (AspectRatio * 2);
step = 360 / MAXPTS; /* Determine # of increments */
angle = 0; /* Begin at zero degrees */
for( i=0 ; irads = (double)angle * PI / 180.0; /* Convert angle to radians */
points.x = xcenter + (int)( cos(rads) * radius );
points.y = ycenter - (int)( sin(rads) * radius * AspectRatio );
angle += step; /* Move to next increment */
}
circle( xcenter, ycenter, radius ); /* Draw bounding circle */
for( i=0 ; ifor( j=i ; jmoveto(points.x, points.y); /* Move to beginning of cord */
lineto(points[j].x, points[j].y); /* Draw the cord */
} } }
main()
{int driver,mode;
driver=CGA;mode=CGAC0;
initgraph(&driver,&mode,"");
setcolor(3);
setbkcolor(GREEN);
LineToDemo();}