www.1kg.org

不然做TopCoder的时候总是吃亏。

在此，还要感谢Linda指出了多处错误。

using System;

namespace TopCoderLibrary
{
    class Geometry
    {
        // maximum Integer
        int maxInt { get { return 2 ^ 31 - 1; } }

        // miminum Integer
        int minInt { get { return -2 ^ 31; } }

        // point (x,y)
        class XYpoint
        {
            public XYpoint() { }
            public XYpoint(double _x, double _y) { x = _x; y = _y; }
            public double x, y;
        }

        // line in the format of Ax+By+C=0 defined by a,b, and c
        class XYline
        {
            public XYline() { }
            public XYline(double _A, double _B, double _C) { A = _A; B = _B; C = _C; }
            public XYline(XYpoint a, XYpoint b) :
                this(b.y - a.y, a.x - b.x, a.y*b.x - a.x*b.y) { }
            public double A, B, C;
        }

        // line segment ab
        class XYsegment
        {
            public XYsegment() { }
            public XYsegment(XYpoint _a, XYpoint _b) { a = _a; b = _b; }
            public XYpoint a, b;
        }

        // polygon
        class XYpolygon
        {
            public XYpolygon(XYpoint[] _ps) { ps = _ps; }
            public XYpoint[] ps;
        }

        // distance from point a to point b
        double distance(XYpoint a, XYpoint b)
        {
            return Math.Sqrt((a.x - b.x) * (a.x - b.x) + (a.y - b.y) * (a.y - b.y));
        }

        // distance from point a to line l
        double distance(XYpoint a, XYline l)
        {
            return Math.Abs(l.A * a.x + l.B * a.y + l.C) / Math.Sqrt(l.A * l.A + l.B * l.B);
        }

        // the area of triangle with vetices points a, b, and c
        double area(XYpoint a, XYpoint b, XYpoint c)
        {
            return Math.Abs(0.5 * ((c.y - a.y) * (b.x - a.x) - (b.y - a.y) * (c.x - a.x)));
        }

        // if Intersect Lines
        bool isIL(XYline l1, XYline l2)
        {
            return l1.A * l2.B != l1.B * l2.A;
        }

        // if Parallel Lines
        bool isPL(XYline l1, XYline l2)
        {
            return l1.A * l2.B == l1.B * l2.A &&
                !(l1.A * l2.C == l1.C * l2.A && l1.B * l2.C == l1.C * l2.B);
        }

        // if Ovevlapping Lines
        bool isOL(XYline l1, XYline l2)
        {
            return l1.A * l2.B == l1.B * l2.A && l1.A * l2.C == l1.C * l2.A && l1.B * l2.C == l1.C * l2.B;
        }

        // get Intersect Point
        XYpoint getIP(XYline l1, XYline l2)
        {
            if (l1.A * l2.B == l1.B * l2.A) return new XYpoint();
            return new XYpoint(-(l1.C * l2.B - l2.C * l1.B) / (l1.A * l2.B - l2.A * l1.B),
                -(l1.C * l2.A - l2.C * l1.A) / (l1.B * l2.A - l2.B * l1.A));
        }

        // get the Inclination Angle of two lines l1, l2 (in radian value)
        double angle_LL(XYline l1, XYline l2)
        {
            if ((l1.A * l2.A + l1.B * l2.B) == 0) return 1e100;
            return Math.Atan(Math.Abs((l1.A * l2.B - l2.A * l1.B) / (l1.A * l2.A + l1.B * l2.B)));
        }

        // get line l's perpendicular line, which passing through point p
        XYline getPL(XYpoint p, XYline l)
        {
            return new XYline(l.B, -l.A, -l.B * p.x + l.A * p.y);
        }

        // if segment abc is turning Clock Wise on point b
        bool isCW(XYpoint a, XYpoint b, XYpoint c)
        {
            return ((b.x - a.x) * (c.y - a.y) - (c.x - a.x) * (b.y - a.y) > 0);
        }

        // if segment abc is turning Counter Clock Wise on point b
        bool isCCW(XYpoint a, XYpoint b, XYpoint c)
        {
            return ((b.x - a.x) * (c.y - a.y) - (c.x - a.x) * (b.y - a.y) < 0);
        }

        // if three points a, b, and c are collinear points
        bool isCP(XYpoint a, XYpoint b, XYpoint c)
        {
            return ((b.x - a.x) * (c.y - a.y) - (c.x - a.x) * (b.y - a.y) == 0);
        }

        // if two segments have intersection points
        bool isIS(XYsegment u, XYsegment v)
        {
            return ((Math.Max(u.a.x, u.b.x) >= Math.Min(v.a.x, v.b.x)) &&
                (Math.Max(v.a.x, v.b.x) >= Math.Min(u.a.x, u.b.x)) &&
                (Math.Max(u.a.y, u.b.y) >= Math.Min(v.a.y, v.b.y)) &&
                (Math.Max(v.a.y, v.b.y) >= Math.Min(u.a.y, u.b.y)) &&
                (isCP(v.a, u.b, u.a) || isCP(u.b, v.b, u.a) || isCW(v.a, u.b, u.a) == isCW(u.b, v.b, u.a)) &&
                (isCP(u.a, v.b, v.a) || isCP(v.b, u.b, v.a) || isCW(u.a, v.b, v.a) == isCW(v.b, u.b, v.a)));
        }

        // if Point p is On Segment l
        bool isPOS(XYsegment l, XYpoint p)
        {
            return isCP(l.a, l.b, p) && p.x >= Math.Min(l.a.x, l.b.x) && p.x <= Math.Max(l.a.x, l.b.x) &&
                p.y >= Math.Min(l.a.y, l.b.y) && p.y <= Math.Max(l.a.y, l.b.y);
        }

        // if Point p is Inside Polygon p
        bool isPIP(XYpoint p, XYpolygon g)
        {
            XYpoint[] ver = new XYpoint[g.ps.Length + 1];
            double mr = g.ps[0].x;
            for (int i = 0; i < ver.Length; i++)
            {
                ver[i] = g.ps[i % g.ps.Length];
                mr = Math.Max(mr, ver[i].x);
            }

            bool ret = false;
            XYsegment line = new XYsegment(p, new XYpoint(mr, p.y));
            for (int i = 0; i < g.ps.Length; i++)
            {
                XYsegment edge = new XYsegment(ver[i], ver[i + 1]);
                if (isPOS(edge, p))
                    return true;
                if (isIS(line, edge))
                    ret = !ret;
            }

            return ret;
        }
    }
}

上次过关带了个桔子，居然被没收了。

TopCoder中看到的一行

template<class T, class V>
vector<T> operator, (vector<T> v, V t) {
  v.push_back(t);
  return v;
}

然后可以写

VI vi = (VI(), 1, 2, 3);

昨天炖的鸡还剩一半，

鸡汤里头下个方便面，

还是少点来个煎鸡蛋，

最后还要炸点馒头片。

我多想请大家吃个饭，但是Linda没有回来。

巧克力的麻烦是：你把它吃了，它就没了。
很像是小梅的口吻。

梦里我参加了一个数学考试，居然没有做完。高中时候发生这样的事，是要互相抽耳光的。

嗯，今天起要多参加一些TopCoder。

我寻找化石多年，数次欲买而未果，具是觉得真他妈贵。
回到家发现老爸有一个恐龙蛋化石，在厂里放了多年一直不让我知道。
问了来由，说是施工的时候用推土机挖出来一窝，自留一个，其余都送人。

大概有脑袋这么大，很是沉。