static bool IsTouch(Cricle c, int x1,int y1,int x2,int y2)
{
var LL = SquareDis(x1, y1, x2, y2);
var rr = c.R * c.R;
var K = SquareDis(c.xc, c.yc, x2, y2) + SquareDis(x1, y1,c.xc, c.yc) - 2 * rr;
if (2 * K - LL < 0 || K > LL)
{
return false;
}
else {
return true;
}
}
static string IsCross(Cricle c,Triangle t)
{
var d1 = SquareDis(c.xc, c.yc, t.GetPointX(0), t.GetPointY(0));
var d2 = SquareDis(c.xc, c.yc, t.GetPointX(1), t.GetPointY(1));
var d3 = SquareDis(c.xc, c.yc, t.GetPointX(2), t.GetPointY(2));
var RSquare = c.R * c.R;
if ((d1 < RSquare && d2 < RSquare && d3 < RSquare) )
{
return "NO";
}
else if ((d1 > RSquare && d2 > RSquare && d3 > RSquare))
{
if (IsTouch(c, t.GetPointX(0), t.GetPointY(0), t.GetPointX(1), t.GetPointY(1))||
IsTouch(c, t.GetPointX(0), t.GetPointY(0), t.GetPointX(2), t.GetPointY(2))||
IsTouch(c, t.GetPointX(2), t.GetPointY(2), t.GetPointX(1), t.GetPointY(1)))
return "YES";
return "NO";
}
else {
return "YES";
}
}
