获取连续的日期范围

Question

给定一个日期范围列表，我想获得一个连续日期范围的列表。

我不太确定我正在寻找的术语，但我整理了一个框架：

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

namespace ContiguousTimeSpans
{
    class Program
    {
        static void Main(string[] args)
        {
            List<DateRange> ranges = new List<DateRange>();
            ranges.Add(new DateRange(DateTime.Parse("01/12/2015 07:00:00"), DateTime.Parse("01/12/2015 10:00:00")));
            ranges.Add(new DateRange(DateTime.Parse("01/12/2015 06:00:00"), DateTime.Parse("01/12/2015 09:00:00")));
            ranges.Add(new DateRange(DateTime.Parse("01/12/2015 05:00:00"), DateTime.Parse("01/12/2015 08:00:00")));
            ranges.Add(new DateRange(DateTime.Parse("01/12/2015 18:00:00"), DateTime.Parse("01/12/2015 21:00:00")));
            ranges.Add(new DateRange(DateTime.Parse("01/12/2015 12:00:00"), DateTime.Parse("01/12/2015 14:00:00")));
            ranges.Add(new DateRange(DateTime.Parse("01/12/2015 20:00:00"), DateTime.Parse("01/12/2015 22:00:00")));
            ranges.Add(new DateRange(DateTime.Parse("01/12/2015 11:00:00"), DateTime.Parse("01/12/2015 23:00:00")));

            List<DateRange> contiguousBlocks = GetContiguousTimespans(ranges);
            Debug.Assert(contiguousBlocks.Count == 2);

            Debug.Assert(contiguousBlocks[0].Start.Hour == 5);
            Debug.Assert(contiguousBlocks[0].End.Hour == 10);

            Debug.Assert(contiguousBlocks[1].Start.Hour == 11);
            Debug.Assert(contiguousBlocks[1].End.Hour == 23);

            Console.ReadKey();
        }

        public static List<DateRange> GetContiguousTimespans(List<DateRange> ranges)
        {
            List<DateRange> result = new List<DateRange>();
            //???
            return result;
        }
    }

    public class DateRange
    {
        public DateTime Start { get; set; }
        public DateTime End { get; set; }

        public DateRange(DateTime start, DateTime end)
        {
            Start = start;
            End = end;
        }
    }
}

有没有办法推断出连续的范围？

Answer 1

不确定我是否完全理解这一点，但关于所写内容和测试数据，这应该有效：

public static List<DateRange> GetContiguousTimespans(List<DateRange> ranges)
{
    List<DateRange> result = new List<DateRange>();
    ranges.Sort((a,b)=>a.Start.CompareTo(b.Start));
    DateRange cur = ranges[0];

    for (int i = 1; i < ranges.Count; i++)
    {
        if (ranges[i].Start <= cur.End)
        {
            if (ranges[i].End >= cur.End)
                cur.End = ranges[i].End;
        }
        else
        {
            result.Add(cur);
            cur = ranges[i];
        }
    }

    result.Add(cur);

    return result;
}

当然这也需要添加一些边界值的检查，但我想总体思路应该很清楚。

Answer 2

谢谢猕猴桃。我查看了 Time Period Library，它有一个名为 'Time Period Combiner' 的功能，这正是我要找的。

在我的案例中使用它的代码是：

public static List<DateRange> GetContiguousTimespans(List<DateRange> ranges)
{
    //convert my DateRange objects into the objects used by the Time Period Library
    TimePeriodCollection periods = new TimePeriodCollection();
    ranges.ForEach(ts => periods.Add(new TimeRange(ts.Start, ts.End)));

    //get a list of contiguous date ranges
    TimePeriodCombiner<TimeRange> periodCombiner = new TimePeriodCombiner<TimeRange>();
    ITimePeriodCollection combinedPeriods = periodCombiner.CombinePeriods(periods);

    //convert the objects back to DateRanges
    List<DateRange> result = combinedPeriods.Select(cp => new DateRange(cp.Start, cp.End)).ToList();
    return result;
}

Answer 3

所以如果我从这个输入开始：

List<DateRange> ranges = new List<DateRange>()
{
    new DateRange(DateTime.Parse("01/12/2015 07:00:00"), DateTime.Parse("01/12/2015 10:00:00")),
    new DateRange(DateTime.Parse("01/12/2015 06:00:00"), DateTime.Parse("01/12/2015 09:00:00")),
    new DateRange(DateTime.Parse("01/12/2015 05:00:00"), DateTime.Parse("01/12/2015 08:00:00")),
    new DateRange(DateTime.Parse("01/12/2015 18:00:00"), DateTime.Parse("01/12/2015 21:00:00")),
    new DateRange(DateTime.Parse("01/12/2015 12:00:00"), DateTime.Parse("01/12/2015 14:00:00")),
    new DateRange(DateTime.Parse("01/12/2015 20:00:00"), DateTime.Parse("01/12/2015 22:00:00")),
    new DateRange(DateTime.Parse("01/12/2015 11:00:00"), DateTime.Parse("01/12/2015 23:00:00")),
};

那么这对我有用：

var ordered = ranges.OrderBy(x => x.Start).ThenBy(x => x.End).ToArray();

var working =
    ordered
        .Skip(1)
        .Aggregate(new
        {
            contiguous = new List<DateRange>(),
            current = ordered.First(),
        }, (a, r) =>
        {
            if (a.current.End >= r.Start)
            {
                return new
                {
                    a.contiguous,
                    current = r.End > a.current.End
                        ? new DateRange(a.current.Start, r.End)
                        : a.current,
                };
            }
            else
            {
                a.contiguous.Add(a.current);
                return new
                {
                    a.contiguous,
                    current = r,
                };
            }
        });

var results = working.contiguous;
results.Add(working.current);

我得到的最终结果是这样的：

获取连续的日期范围

Get contiguous date ranges

c#

datetime

timespan