#include"graphics.h"
#include"math.h"
void main()
{    float val[]={3.9,5.3,7.2,9.6,12.,10.0,23.2,31.4,39.8,50.2,62.9,56.0,92.0,105.7,122.8,125.7,150.7,179.3,203.2,211.0};
    char *ch[]={"1","2","3","4","5","6","7","8","9","10","11","12","13","14","15","16","17","18","19","20"};
    int i,j,x1,x2,y1,y2,n;
    char str[10];
    int graphdriver=DETECT,graphmode;
    registerbgidriver(EGAVGA_driver);
    initgraph(&graphdriver,&graphmode," ");
    cleardevice();
    setviewport(20,20,570,450,1);
    setcolor(1);
    n=20;
    x1=80;
    y1=390-1.5*val[0];
    for(i=0;i<=n-1;i++)
    {    x2=x1+20;
        y2=390-1.5*val[i];
        setcolor(12);
        line(x1,y1,x2,y2);
        setcolor(WHITE);
        circle(x2,y2,1);
        }
    setcolor(WHITE);
    line(80,390,500,390);
    j=0;
    for(i=100;i<=80+n*20;i=i+20)
    {    line(i,390,i,400);
        outtextxy(i-4,450,ch[j]);
        j++;
        }
    outtextxy(200,420,"Every times");
    line(80,390,80,5);
    for(j=0;j<=300;j=j+50)
    {    line(70,390-1.5*j,80,390-1.5*j);
        sprintf(str,"%d",j);
        outtextxy(45,390-1.5*j-3,str);
        }
    settextstyle(0,1,1);
    outtextxy(30,40,"Values");
    getch();
    closegraph();
    }
中的x1=80;
    y1=390-1.5*val[0];
    for(i=0;i<=n-1;i++)
    {    x2=x1+20;
        y2=390-1.5*val[i];
        setcolor(12);
        line(x1,y1,x2,y2);
        setcolor(WHITE);
        circle(x2,y2,1);
        }
怎么理解啊？

registerbgidriver(EGAVGA_driver);
    initgraph(&graphdriver,&graphmode," ");
    cleardevice();
    setviewport(20,20,570,450,1);
    setcolor(1);

这几个是调用库函数  好像是颜色的调节

剩下的我也懒得看了  只能告诉你颜色是由RGB宏来决定的 每个是0--255

每个8位  一共24位

我请教的是下面的内容

抱歉实在看着有点纠结

期待ing