查找不连续日期时间列表，C＃，LINQ

Question

该算法是基于在一个DateTime列表中找到所述缺少的日期和分组日期的块，如果他们是第二开，或者具有其他的时间间隔

DateTime startDate = DateTime.Now; 
Random rnd = new Random(); 
List<DateTime> datesList = new List<DateTime>(); 
List<List<DateTime>> segregatedList = new List<List<DateTime>>(); 
var oneYear = 60*60*24*365; 
///////////////////// INPUT GENERATE ///////////////////// 
for (var i = 0; i < oneYear; ++i) 
{ 
    if (rnd.Next(1, 5) == 4) continue; 
    datesList.Add(startDate.AddSeconds(i)); 
} 
/////////////////////// ALGORITHM /////////////////////// 
segregatedList.Add(new List<DateTime>()); 
var difference = datesList[1] - datesList[0]; 
var j = 0; 
var lastIndex = datesList.Count - 1; 


for (var i = 0; i < datesList.Count; ++i) 
{ 
    segregatedList[j].Add(datesList[i]); 

    if (i == lastIndex) continue; 
    if ((datesList[i + 1] - datesList[i]) == difference) 
    { 
     difference = datesList[i + 1] - datesList[i]; 
     continue; 
    } 
    segregatedList.Add(new List<DateTime>()); 
    ++j; 
} 

我想知道是否有能力在LINQ中编写此代码。

Answer 1

如果我认为你其实只是想按日期组/次是第二相隔那么这是LINQ版本：

DateTime startDate = DateTime.Now; 
Random rnd = new Random(); 
var oneYear = 60*60*24*365; 

List<DateTime> datesList = 
    Enumerable 
     .Range(0, oneYear) 
     .Where(i => rnd.Next(1, 5) != 4) 
     .Select(i => startDate.AddSeconds(i)) 
     .ToList(); 

List<List<DateTime>> segregatedList = 
    datesList 
     .Skip(1) 
     .Aggregate(
      datesList 
       .Take(1) 
       .Select(x => new List<DateTime>() { x }) 
       .ToList(), 
       (a, x) => 
       { 
        if (x.Subtract(a.Last().Last()) == TimeSpan.FromSeconds(1.0)) 
        { 
         a.Last().Add(x); 
        } 
        else 
        { 
         a.Add(new List<DateTime>() { x }); 
        } 
        return a; 
       });