[2015][Homework]Team04-Hw05

Program為進入程式點，輸入與輸出
Point為類別，計算兩點距離
PinBoard為類別，產生pinboard格點座標
Triangle為類別，產生triangle並計算周長、面積、外接圓半徑

Program

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace homework5
{
    class Program
    {
        static void Main(string[] args)
        {
            PinBoard board = new PinBoard();
            Triangle tri = new Triangle();
            Random rand = new Random();

            while (true)
            {
                Console.WriteLine("Please input rows and columns");

            Rows:
                Console.WriteLine("How many rows?");      //input rows
                board.rows = int.Parse(Console.ReadLine());
                if (board.rows <= 0)
                {
                    Console.WriteLine("Must be a positive integer!");
                    goto Rows;
                }

            Columns:
                Console.WriteLine("How many columns?");      //input columns
                board.columns = int.Parse(Console.ReadLine());
                if (board.columns <= 0)
                {
                    Console.WriteLine("Must be a positive integer!");
                    goto Columns;
                }

                Console.WriteLine("Please input interval between points");

            XInterval:
                Console.WriteLine("Interval along x-axis?");      //input x-interval
                board.xInterval = double.Parse(Console.ReadLine());
                if (board.xInterval <= 0)
                {
                    Console.WriteLine("Must be positive!");
                    goto XInterval;
                }

            YInterval:
                Console.WriteLine("Interval along y-axis?");      //input y-interval
                board.yInterval = double.Parse(Console.ReadLine());
                if (board.yInterval <= 0)
                {
                    Console.WriteLine("Must be positive!");
                    goto YInterval;
                }

                board.CreatePins();
                board.SetPinPosition();

                for (int i = 0; i <= 2; i++)      //create three points (x,y) randomly
                {
                    tri.pointArray[i] = board.pinArray[rand.Next(board.rows), rand.Next(board.columns)];
                }

                Console.WriteLine("Position of three points that form a triangle are:");      //output answers
                for (int i = 0; i <= 2; i++)
                {
                    Console.WriteLine("({0},{1})", tri.pointArray[i].x, tri.pointArray[i].y);
                }
                Console.WriteLine("Perimeter = {0}", tri.Perimeter());
                Console.WriteLine("Area = {0}", tri.Area());
                Console.WriteLine("Radius of circumcircle = {0}", tri.RadiusOfCircumcircle());

                Console.WriteLine("Again? (Y or N)");
                string select = Console.ReadLine();
                if (("y" != select) && ("Y" != select))
                {
                    break;
                }
            }
            Console.Read();
        }
    }
}

Point

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace homework5
{
    class Point
    {
        public double x;
        public double y;

        public double DistanceTo(Point p)      //calculate distance between two points
        {
            return Math.Sqrt((this.x - p.x) * (this.x - p.x) + (this.y - p.y) * (this.y - p.y));
        }
    }
}

PinBoard

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace homework5
{
    class PinBoard
    {
        public int rows;
        public int columns;
        public double xInterval;
        public double yInterval;
        public Point[,] pinArray = null;

        public void CreatePins()      //create pins array
        {
            pinArray = new Point[rows, columns];
            for (int i = 0; i < rows; i++)
            {
                for (int j = 0; j < columns; j++)
                {
                    pinArray[i, j] = new Point();
                }
            }
        }

        public void SetPinPosition()      //set pins position (x,y)
        {
            double xPosition;
            double yPosition;

            yPosition = 0;
            for (int i = 0; i < rows; i++)
            {
                xPosition = 0;
                for (int j = 0; j < columns; j++)
                {
                    pinArray[i, j].x = xPosition;
                    pinArray[i, j].y = yPosition;
                    xPosition += xInterval;
                }
                yPosition += yInterval;
            }
        }
    }
}

Triangle

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace homework5
{
    class Triangle
    {
        public Point[] pointArray = new Point[3];

        public double Perimeter()      //calculate triangle perimeter
        {
            double length1 = pointArray[0].DistanceTo(pointArray[1]);
            double length2 = pointArray[1].DistanceTo(pointArray[2]);
            double length3 = pointArray[2].DistanceTo(pointArray[0]);
            return (length1 + length2 + length3);
        }

        public double Area()      //calculate triangle area
        {
            double length1 = pointArray[0].DistanceTo(pointArray[1]);
            double length2 = pointArray[1].DistanceTo(pointArray[2]);
            double length3 = pointArray[2].DistanceTo(pointArray[0]);
            double length = (length1 + length2 + length3) / 2;
            return Math.Sqrt(length * (length - length1) * (length - length2) * (length - length3));
        }

        public double RadiusOfCircumcircle()      //calculate radius of circumcircle of triangle
        {
            double length1 = pointArray[0].DistanceTo(pointArray[1]);
            double length2 = pointArray[1].DistanceTo(pointArray[2]);
            double length3 = pointArray[2].DistanceTo(pointArray[0]);
            double cosAngle = (length2 * length2 + length3 * length3 - length1 * length1) / (2 * length2 * length3);
            double sinAngle = Math.Sqrt(1 - cosAngle * cosAngle);
            return 0.5 * length1 / sinAngle;
        }
    }
}