检查两个日期是否以任何可能的方式重叠

Question

我需要检查 DateTime-span 是否与任何现有的时间块重叠。

我的函数应该检查是否有任何重叠 并且将运行数百次，新的开始和结束日期之间的时间跨度为 10 分钟。 现有时间块的跨度可能是 5-60 分钟长。

收到的第一个 span 始终是最早的日期，收到的最后一个 span 始终是最晚的日期。 existingTimeBlocks 列表也按 StartDate 排序

    private bool TimeBlockIsOverLapping(DateTime newTimeBlockStart, DateTime newTimeBlockEnd, IEnumerable<TimeBlock> existingTimeBlocks)
    {
        // The new TimeBlock starts later than latest existing TimeBlock or ends earlier that first existing timeblock so it won't overlap
        if (existingTimeBlocks.Count() == 0)
        {
            return false;
        }

        // The new TimeBlock is within the scope of old TimeBlocks and might overlap
        else
        {
            // TODO: Insert overlap checks here
        }
    }

编辑：TimeBlock 的简化定义：

public class TimeBlock
    {
        [Required]
        public int Id { get; set; }

        [Required]
        public DateTime StartTime { get; set; }

        [Required]
        public DateTime EndTime { get; set; }

        [Required]
        public int ScheduleId { get; set; }

        [Required]
        public virtual Schedule Schedule { get; set; }
    }

编辑：进一步澄清： existingTimeBlocks 可以是例如每周一和周四的 9:00 - 12:00 和 13:00-16:00 共 6 周，因此可以在周一的 12:00 和 13:00 之间传递 60 分钟的 timeSpan 和有效

Answer 1

类似：

private static bool TimeBlockIsOverLapping(DateTime newTimeBlockStart, DateTime newTimeBlockEnd, IEnumerable<TimeBlock> existingTimeBlocks) {
    foreach (var block in existingTimeBlocks) {
        // This is only if existingTimeBlocks are ordered. It is only
        // a speedup
        if (newTimeBlockStart > block.EndTime) {
            break;
        }

        // This is the real check. The ordering of the existingTimeBlocks
        // is irrelevant
        if (newTimeBlockStart <= block.EndTime && newTimeBlockEnd >= block.StartTime) {
            return true;
        }
    }

    return false;
}

为了检查重叠块，我使用了Algorithm to detect overlapping periods

Answer 2

好吧，让我们来实现：

// static: we don't want "this" in the context
private static bool TimeBlockIsOverLapping(DateTime newTimeBlockStart, 
                                           DateTime newTimeBlockEnd, 
                                           IEnumerable<TimeBlock> existingTimeBlocks) {
  if (null == existingTimeBlocks)
    return false;
  else if (newTimeBlockStart > newTimeBlockEnd)
    return false;

  // assuming that there' no null blocks within existingTimeBlocks
  // and all blocks within existingTimeBlocks are valid ones
  foreach (var block in existingTimeBlocks) {
    //TODO: check edges: < or <=; > or >=
    if ((newTimeBlockStart < block.EndTime) && (newTimeBlockEnd > block.StartTime))
      return true; // overlap found
  }  

  return false; // no overlap found  
}

Answer 3

假设您的时间块包含开始日期和结束日期，请使用 OverlapsWith 函数...

public class TimeBlock
{
    public DateTime EndTime {get;set;}
    public DateTime StartTime {get;set;}

    public bool OverlapsWith(TimeBlock other)
    {
        return (StartTime <= other.StartTime && EndTime >= other.StartTime)
            || (StartTime <= other.EndTime && EndTime >= other.EndTime);
    }
}

然后在你的函数中......

var myBlock = new TimeBlock{ EndTime = newTimeBlockEnd, StartTime = newTimeBlockStart};
if(existingTimeBlocks.Any(x => x.OverlapsWith(myBlock)))
   // ...your code