画线条

#include<graphics.h>
#include<conio.h>
int main()
{
    initgraph(640,480);
    for(int y=100;y<=300;)
    {
        if(y/10%2==1)
        setcolor(RGB(0,0,255));
        else
        setcolor(RGB(255,0,0));
        line(100,y,300,y);
        y+=10;
    }
    getch();
  closegraph();
}