using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        int[][] rectangles1 = new int[][] {new int[]{1,1,3,3}, new int[]{3,1,4,2}, new int[]{3,2,4,4}, new int[]{1,3,2,4}, new int[]{2,3,3,4}};

        Console.WriteLine(PerfectRectangle.IsRectangle(rectangles1));

        int[][] rectangles2 = new int[][]{new int[]{1,1,2,3}, new int[]{1,3,2,4}, new int[]{3,1,4,2}, new int[]{3,2,4,4}};

        Console.WriteLine(PerfectRectangle.IsRectangle(rectangles2));

        int[][] rectangles3 = new int[][]{new int[]{1,1,3,3}, new int[]{3,1,4,2}, new int[]{1,3,2,4}, new int[]{3,2,4,4}};

        Console.WriteLine(PerfectRectangle.IsRectangle(rectangles3));

        int[][] rectangles4 = new int[][]{new int[]{1,1,3,3}, new int[]{3,1,4,2}, new int[]{1,3,2,4}, new int[]{2,2,4,4}};

        Console.WriteLine(PerfectRectangle.IsRectangle(rectangles4));

        int[][] rectangles5 = new int[][]{new int[]{1,1,3,3}, new int[]{3,1,4,2}, new int[]{1,3,2,4}, new int[]{3,2,4,4}, new int[]{2,3,3,4}};

        Console.WriteLine(PerfectRectangle.IsRectangle(rectangles5));

    }

}

​

public static class PerfectRectangle

{

    public static bool IsRectangle(int[][] rectArray)

    {

        int totalArea = 0;

        int maxX=0,minX=0,maxY=0,minY = 0;

        if(rectArray.Length == 0)

            return false;

        List<Point> listOfPoints = new List<Point>();

        foreach(int[] rect in rectArray)

        {

            listOfPoints = CheckAllCornersOfRectangleInPointList(listOfPoints, rect);

            totalArea += GetArea(rect[0], rect[2], rect[1], rect[3]);

                minX = (minX > rect[0])? rect[0] : minX;

                minX = (minX > rect[2])? rect[2] : minX;

                maxX = (maxX < rect[0])? rect[0] : maxX;

                maxX = (maxX < rect[2])? rect[2] : maxX;

                minY = (minY > rect[1])? rect[1] : minY;

                minY = (minY > rect[3])? rect[3] : minY;

                maxY = (maxY < rect[1])? rect[1] : maxY;

                maxY = (maxY < rect[3])? rect[3] : maxY;

        }

        if(listOfPoints.Count() > 4 || totalArea != GetArea(minX,maxX,minY,maxY))

            return false;

        return true;

    }

    private static List<Point> CheckAllCornersOfRectangleInPointList(List<Point> pointList, int[] rectangle)

    {

        pointList = CheckPointExistsInList(pointList , rectangle[0], rectangle[1]);

        pointList = CheckPointExistsInList(pointList , rectangle[0], rectangle[3]);

        pointList = CheckPointExistsInList(pointList , rectangle[2], rectangle[1]);

        pointList = CheckPointExistsInList(pointList , rectangle[2], rectangle[3]);

        return pointList;

    }

    private static List<Point> CheckPointExistsInList(List<Point> pointList, int x, int y)

    {

        if(pointList.Any(a => a.X == x && a.Y == y))

                pointList.RemoveAll(b =>  b.X == x && b.Y == y);

        else

                pointList.Add(new Point(x,y));

           return pointList;

    }

    private static int GetArea(int x2, int x1, int y2, int y1)

    {

        return (Math.Abs(y2-y2)* Math.Abs(x2-x1));

    }

}

​

public class Point

{

    public int X;

    public int Y;

    public Point(int x, int y)

    {

        X=x;Y=y;

    }

}