Question

我有一个linkedList，其中包含有关一个点的信息：它的颜色，其x和y坐标。

Color: Red  | X coordinate: 5   |  Y coordinate: 7
Color: Blue  | X coordinate: 6   |  Y coordinate: 5
Color: Red  | X coordinate: 2   |  Y coordinate: 4
Color: Blue  | X coordinate: 3   |  Y coordinate: 0
Color: Red  | X coordinate: 0   |  Y coordinate: 0
Color: Blue  | X coordinate: 0   |  Y coordinate: 5
Color: Yellow  | X coordinate: 1   |  Y coordinate: 4
Color: Yellow  | X coordinate: 2   |  Y coordinate: 3
Color: Yellow  | X coordinate: 1   |  Y coordinate: 1

我需要找到一个颜色不匹配的三角形，并找到其周长。我该怎么做？

我的最终输出应该是：

Color: Red      |   Perimter: {}    |
Color: Blue     |   Perimeter: {}   |
Color: Yellow   |   Perimeter: {}   |

Answer 1

尝试以下代码：

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

namespace ConsoleApplication107
{
    class Program
    {
        static void Main(string[] args)
        {

            List<Point> points = new List<Point>() {
                new Point() { Color = "Red", X = 5, Y = 7},
                new Point() { Color = "Blue", X = 6, Y = 5},
                new Point() { Color = "Red", X = 2, Y = 4},
                new Point() { Color = "Blue", X = 3, Y = 0},
                new Point() { Color = "Red", X = 0, Y = 0},
                new Point() { Color = "Blue", X = 0, Y = 5},
                new Point() { Color = "Yellow", X = 1, Y = 4},
                new Point() { Color = "Yellow", X = 2, Y = 3},
                new Point() { Color = "Yellow", X = 1, Y = 1}
            };

            //create link list
            LinkedList<Point> list = new LinkedList<Point>();
            foreach (Point point in points)
            {
                list.AddLast(point);
            }

            var results = list.GroupBy(x => x.Color).Select(x => new { color = x.Key, perimeter = x.Select(y => new { X = y.X, Y = y.Y }).ToList() }).ToList();

        }
    }
    public class Point
    {
        public string Color { get; set; }
        public int X { get; set; }
        public int Y { get; set; }
    }


}

Answer 2

您可以从计算策略链长度的方法开始：

private static double CalculatePerimeter(List<(int x, int y)> points)
{
    if (points.Count < 2)
        throw new ArgumentException("Should be at least two points", "points");

    // for triangles
    // if (points.Count != 3)
    //    throw new ArgumentException("Triangle should have only three points", "points");

    var lastPoint = points[0];
    var perimeter = 0.0;
    for (var i = 1; i < points.Count; ++i)
    {
        var currentPoint = points[i];
        perimeter += Math.Sqrt(
            Math.Pow(currentPoint.x - lastPoint.x, 2) +
            Math.Pow(currentPoint.y - lastPoint.y, 2));

        lastPoint = currentPoint;
    }

    return perimeter;
}

现在，您需要按颜色对点进行分组，并在每个组中的所有点上调用CalculatePerimeter：

var input = new[]
{
    new {color = "Red", X = 5, Y = 7},
    new {color = "Blue", X = 6, Y = 5},
    new {color = "Red", X = 2, Y = 4},
    new {color = "Blue", X = 3, Y = 0},
    new {color = "Red", X = 0, Y = 0},
    new {color = "Blue", X = 0, Y = 5},
    new {color = "Yellow", X = 1, Y = 4},
    new {color = "Yellow", X = 2, Y = 3},
    new {color = "Yellow", X = 1, Y = 1},
};

var result = input
    .GroupBy(x => x.color)
    .Select(g => new {color = g.Key, perimeter = CalculatePerimeter(g.Select(p => (x : p.X, y: p.Y)).ToList())});

foreach (var triangle in result)
    Console.WriteLine($"Triangle color {triangle.color}, perimeter {triangle.perimeter}");

输出将是：

三角形颜色红色，周长8,71477664211886
  三角形颜色蓝色，周长11,6619037896906
  三角形颜色黄色，周长3,65028153987288

使用链接列表在具有x和y坐标的点上形成三角形

2 个答案: