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Merge interval with merge distance in C#

Given a list of intervals [start, end] I have to merge them based on a specified merge distance. The intervals are arriving in a particular order, and as they arrive it should merge them according to the specified merge distance as each interval is received. Some of these intervals will be removed (in the arrival stream they will be marked as removed) – in that situation I've to treat the original interval as if it never existed. Example:
Merge distance is 7 – in the following example the input is arriving in order
I've tried the following algorithm to merge them but my Output isn't coming like the above example. Can somebody assists me, what I'm missing here!
Here is my code.
class Program
{
static void Main(string[] args)
{
var intervals = new List<Interval>
{
new Interval
{
start = 1,
end = 20
},
new Interval
{
start = 55,
end = 58
},
new Interval
{
start = 60,
end = 89
},
new Interval
{
start = 15,
end = 31
},
new Interval
{
start = 10,
end = 15
},
new Interval
{
start = 1,
end = 20
}
};
var mergedIntervals = Merge(intervals, 7);
foreach (var item in mergedIntervals)
{
Console.WriteLine($"[{item.start}, {item.end}]");
}
Console.ReadKey();
}
public static List<Interval> Merge(List<Interval> intervals, int mergeDistance)
{
var result = new List<Interval>();
for (int i = 0; i < intervals.Count; i++)
{
var newInterval = new Interval(intervals[i].start, intervals[i].end);
//while (i < intervals.Count - 1 && newInterval.end >= intervals[i + 1].start)
while (i < intervals.Count - 1 && newInterval.end <= mergeDistance) // intervals[i + 1].start)
{
newInterval.end = Math.Max(newInterval.end, intervals[i + 1].end);
i++;
}
result.Add(newInterval);
}
return result;
}
}
public class Interval
{
public int start { get; set; }
public int end { get; set; }
public Interval()
{
}
public Interval(int start, int end)
{
this.start = start;
this.end = end;
}
}

Can you please try this code, working demo code here
class Program
{
static void Main(string[] args)
{
var intervals = new List<Interval>
{
new Interval
{
start = 1,
end = 20,
isAdded = true
},
new Interval
{
start = 55,
end = 58,
isAdded = true
},
new Interval
{
start = 60,
end = 89,
isAdded = true
},
new Interval
{
start = 15,
end = 31,
isAdded = true
},
new Interval
{
start = 10,
end = 15,
isAdded = true
},
new Interval
{
start = 1,
end = 20,
isAdded = false
}
};
var mergedIntervals = Merge(intervals, 7);
foreach (var item in mergedIntervals)
{
Console.WriteLine($"[{item.start}, {item.end}]");
}
Console.ReadKey();
}
public static List<Interval> Merge(List<Interval> intervals, int mergeDistance)
{
var result = new List<IntervalGroup>();
var group = new IntervalGroup();
foreach (var item in intervals)
{
group = result.Where(c => c.Groups.Any(g =>
Math.Abs(g.end - item.start) <= mergeDistance ||
Math.Abs(g.end - item.end) <= mergeDistance)).FirstOrDefault();
if (group != null && item.isAdded)
{
group.Groups.Add(item);
}
else if(item.isAdded)
{
group = new IntervalGroup();
group.Groups = new List<Interval>();
result.Add(group);
group.Groups.Add(item);
}
else if(item.isAdded == false)
{
group.Groups.Remove(group.Groups.Where(c => c.start == item.start && c.end == item.end).First());
}
}
var finalResult = result.Select(s => new Interval { start = s.Groups.Min(min => min.start), end = s.Groups.Max(min => min.end) });
return finalResult.ToList();
}
}
public class Interval
{
public int start { get; set; }
public int end { get; set; }
public bool isAdded { get; set; }
public Interval()
{
}
public Interval(int start, int end, bool isAdded)
{
this.start = start;
this.end = end;
this.isAdded = isAdded;
}
}
public class IntervalGroup
{
public List<Interval> Groups { get; set; }
}

When a problem is beyond your grasp, it is very helpful to break it up into smaller pieces and code the bits that you do understand. Here's how I break it down, step by step.
First, I think it would be convenient to be able to check the length of an interval, so let's add a property.
class Interval
{
/* Prior code */
public int Length => this.end - this.start;
Now let's write a method that merges two intervals:
class Interval
{
/* Prior code */
static public Interval Merge(Interval a, Interval b )
{
return new Interval(Math.Min(a.start, b.start), Math.Max(a.end, b.end));
}
Now we need to write the code that decides if two intervals are capable of being merged. The prototype could look like this:
static public bool CanMerge(Interval a, Interval b, int mergeDistance)
What logic do we need inside? Well, we could check for overlaps and check the merge distance from both ends, but I know a shortcut. Given a merge A + B = C, the merge is allowed if and only if the length of C is less than or equal to the sum of A + B + the merge distance. So we can write this:
class Interval
{
/* Prior code */
static public bool CanMerge(Interval a, Interval b, int mergeDistance)
{
var merged = Merge(a,b);
var canMerge = merged.Length <= a.Length + b.Length + mergeDistance;
return canMerge;
}
From there you can add to a list by checking for mergeable items. Note that recursion is required because the act of merging an interval could result in another interval becoming mergeable.
void AddToList(List<Interval> list, Interval newInterval, int mergeDistance)
{
var target = list.FirstOrDefault( x => Interval.CanMerge(x, newInterval, mergeDistance) );
if (target == null)
{
list.Add(newInterval);
return;
}
list.Remove(target);
AddToList(list, Interval.Merge(target, newInterval), mergeDistance);
}

C#: read text file and process it

I need a program in C# which is write out
how many Eric Clapton songs played in the radios.
is there any eric clapton song which all 3 radios played.
how much time they broadcasted eric clapton songs in SUM.
The first columns contain the radio identification(1-2-3)
The second column is about the song playtime minutes
the third column is the song playtime in seconds
the last two is the performer : song
So the file looks like this:
1 5 3 Deep Purple:Bad Attitude
2 3 36 Eric Clapton:Terraplane Blues
3 2 46 Eric Clapton:Crazy Country Hop
3 3 25 Omega:Ablakok
2 4 23 Eric Clapton:Catch Me If You Can
1 3 27 Eric Clapton:Willie And The Hand Jive
3 4 33 Omega:A szamuzott
.................
And more 670 lines.
so far i get this:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
namespace radiplaytime
{
public struct Adat
{
public int rad;
public int min;
public int sec;
public Adat(string a, string b, string c)
{
rad = Convert.ToInt32(a);
min = Convert.ToInt32(b);
sec = Convert.ToInt32(c);
}
}
class Program
{
static void Main(string[] args)
{
String[] lines = File.ReadAllLines(#"...\zenek.txt");
List<Adat> adatlista = (from adat in lines
//var adatlista = from adat in lines
select new Adat(adat.Split(' ')[0],
adat.Split(' ')[1],
adat.Split(' ')[2])).ToList<Adat>();
var timesum = (from adat in adatlista
group adat by adat.rad into ertekek
select new
{
rad = ertekek.Key,
hour = (ertekek.Sum(adat => adat.min) +
ertekek.Sum(adat => adat.sec) / 60) / 60,
min = (ertekek.Sum(adat => adat.min) +
ertekek.Sum(adat => adat.sec) / 60) % 60,
sec = ertekek.Sum(adat => adat.sec) % 60,
}).ToArray();
for (int i = 0; i < timesum.Length; i++)
{
Console.WriteLine("{0}. radio: {1}:{2}:{3} playtime",
timesum[i].rad,
timesum[i].hour,
timesum[i].min,
timesum[i].sec);
}
Console.ReadKey();
}
}
}

You can define a custom class to store the values of each line. You will need to use Regex to split each line and populate your custom class. Then you can use linq to get the information you need.
public class Plays
{
public int RadioID { get; set; }
public int PlayTimeMinutes { get; set; }
public int PlayTimeSeconds { get; set; }
public string Performer { get; set; }
public string Song { get; set; }
}
So you then read your file and populate the custom Plays:
String[] lines = File.ReadAllLines(#"songs.txt");
List<Plays> plays = new List<Plays>();
foreach (string line in lines)
{
var matches = Regex.Match(line, #"^(\d+)\s(\d+)\s(\d+)\s(.+)\:(.+)$"); //this will split your line into groups
if (matches.Success)
{
Plays play = new Plays();
play.RadioID = int.Parse(matches.Groups[1].Value);
play.PlayTimeMinutes = int.Parse(matches.Groups[2].Value);
play.PlayTimeSeconds = int.Parse(matches.Groups[3].Value);
play.Performer = matches.Groups[4].Value;
play.Song = matches.Groups[5].Value;
plays.Add(play);
}
}
Now that you have your list of songs, you can use linq to get what you need:
//Get Total Eric Clapton songs played - assuming distinct songs
var ericClaptonSongsPlayed = plays.Where(x => x.Performer == "Eric Clapton").GroupBy(y => y.Song).Count();
//get eric clapton songs played on all radio stations
var radioStations = plays.Select(x => x.RadioID).Distinct();
var commonEricClaptonSong = plays.Where(x => x.Performer == "Eric Clapton").GroupBy(y => y.Song).Where(z => z.Count() == radioStations.Count());
etc.

String splitting works only if the text is really simple and doesn't have to deal with fixed length fields. It generates a lot of temporary strings as well, that can cause your program to consume many times the size of the original in RAM and harm performance due to the constant allocations and garbage collection.
Riv's answer shows how to use a Regex to parse this file. It can be improved in several ways though:
var pattern=#"^(\d+)\s(\d+)\s(\d+)\s(.+)\:(.+)$";
var regex=new Regex(pattern);
var plays = from line in File.ReadLines(filePath)
let matches=regex.Match(line)
select new Plays {
RadioID = int.Parse(matches.Groups[1].Value),
PlayTimeMinutes = int.Parse(matches.Groups[2].Value),
PlayTimeSeconds = int.Parse(matches.Groups[3].Value),
Performer = matches.Groups[4].Value,
Song = matches.Groups[5].Value
};
ReadLines returns an IEnumerable<string> instead of returning all of the lines in a buffer. This means that parsing can start immediatelly
By using a single regular expression, we don't have to rebuild the regex for each line.
No list is needed. The query returns an IEnumerable to which other LINQ operations can be applied directly.
For example :
var durations = plays.GroupBy(p=>p.RadioID)
.Select(grp=>new { RadioID=grp.Key,
Hours = grp.Sum(p=>p.PlayTimeMinutes + p.PlayTimeSecons/60)/60,)
Mins = grp.Sum(p=>p.PlayTimeMinutes + p.PlayTimeSecons/60)%60,)
Secss = grp.Sum(p=> p.PlayTimeSecons)%60)
});
A farther improvement could be to give names to the groups:
var pattern=#"^(?<station>\d+)\s(?<min>\d+)\s(?<sec>\d+)\s(?<performer>.+)\:(?<song>.+)$";
...
select new Plays {
RadioID = int.Parse(matches.Groups["station"].Value),
PlayTimeMinutes = int.Parse(matches.Groups["min"].Value),
...
};
You can also get rid of the Plays class and use a single, slightly more complex LINQ query :
var durations = from line in File.ReadLines(filePath)
let matches=regex.Match(line)
let play= new {
RadioID = int.Parse(matches.Groups["station"].Value),
Minutes = int.Parse(matches.Groups["min"].Value),
Seconds = int.Parse(matches.Groups["sec"].Value)
}
group play by play.RadioID into grp
select new { RadioID = grp.Key,
Hours = grp.Sum(p=>p.Minutes + p.Seconds/60)/60,)
Mins = grp.Sum(p=>p.Minutes + p.Seconds/60)%60,)
Secs = grp.Sum(p=> p.Seconds)%60)
};
In this case, no strings are generated for Performer and Song. That's another benefit of regular expressions. Matches and groups are just indexes into the original string. No string is generated until the .Value is read. This would reduce the RAM used in this case by about 75%.
Once you have the results, you can iterate over them :
foreach (var duration in durations)
{
Console.WriteLine("{0}. radio: {1}:{2}:{3} playtime",
duration.RadioID,
duration.Hours,
duration.Mins,
duration.Secs);
}

Filter, merge, sort and page data from multiple sources

At the moment I'm retrieving data from the DB through a method that retrieves an IQueryable<T1>, filtering, sorting and then paging it (all these on the DB basically), before returning the result to the UI for display in a paged table.
I need to integrate results from another DB, and paging seems to be the main issue.
models are similar but not identical (same fields, different names, will need to map to a generic domain model before returning);
joining at the DB level is not possible;
there are ~1000 records at the moment between both DBs (added during
the past 18 months), and likely to grow at mostly the same (slow)
pace;
results always need to be sorted by 1-2 fields (date-wise).
I'm currently torn between these 2 solutions:
Retrieve all data from both sources, merge, sort and then cache them; then simply filter and page on said cache when receiving requests - but I need to invalidate the cache when the collection is modified (which I can);
Filter data on each source (again, at the DB level), then retrieve, merge, sort & page them, before returning.
I'm looking to find a decent algorithm performance-wise. The ideal solution would probably be a combination between them (caching + filtering at the DB level), but I haven't wrapped my head around that at the moment.

I think you can use the following algorithm. Suppose your page size is 10, then for page 0:
Get 10 results from database A, filtered and sorted at db level.
Get 10 results from database B, filtered and sorted at db level (in parallel with the above query)
Combine those two results to get 10 records in the correct sort order. So you have 20 records sorted, but take only first 10 of them and display in UI
Then for page 1:
Notice how many items from database A and B you used to display in UI at previous step. For example, you used 2 items from database A and 8 items from database B.
Get 10 results from database A, filtered and sorted, but starting at position 2 (skip 2), because those two you already have shown in UI.
Get 10 results from database B, filtered and sorted, but starting at position 8 (skip 8).
Merge the same way as above to get 10 records from 20. Suppose now you used 5 item from A and 5 items from B. Now, in total, you have shown 7 items from A and 13 items from B. Use those numbers for the next step.
This will not allow to (easily) skip pages, but as I understand that is not a requirement.
The perfomance should be effectively the same as when you are querying single database, because queries to A and B can be done in parallel.

I've created something here, I will come back with explications if needed.
I'm not sure my algorithm works correctly for all edge cases, it cover all of the cases what I had in mind, but you never know. I'll leave the code here for your pleasure, I will answer and explain what is done there if you need that, leave a comment.
And perform multiple tests with list of items with large gaps between the values.
using System;
using System.Collections.Generic;
using System.Linq;
namespace ConsoleApplication1
{
class Program
{
//each time when this objects are accessed, consider as a database call
private static IQueryable<model1> dbsetModel_1;
private static IQueryable<model2> dbsetModel_2;
private static void InitDBSets()
{
var rnd = new Random();
List<model1> dbsetModel1 = new List<model1>();
List<model2> dbsetModel2 = new List<model2>();
for (int i = 1; i < 300; i++)
{
if (i % 2 == 0)
{
dbsetModel1.Add(new model1() { Id = i, OrderNumber = rnd.Next(1, 10), Name = "Test " + i.ToString() });
}
else
{
dbsetModel2.Add(new model2() { Id2 = i, OrderNumber2 = rnd.Next(1, 10), Name2 = "Test " + i.ToString() });
}
}
dbsetModel_1 = dbsetModel1.AsQueryable();
dbsetModel_2 = dbsetModel2.AsQueryable();
}
public static void Main()
{
//generate sort of db data
InitDBSets();
//test
var result2 = GetPage(new PagingFilter() { Page = 5, Limit = 10 });
var result3 = GetPage(new PagingFilter() { Page = 6, Limit = 10 });
var result5 = GetPage(new PagingFilter() { Page = 7, Limit = 10 });
var result6 = GetPage(new PagingFilter() { Page = 8, Limit = 10 });
var result7 = GetPage(new PagingFilter() { Page = 4, Limit = 20 });
var result8 = GetPage(new PagingFilter() { Page = 200, Limit = 10 });
}
private static PagedList<Item> GetPage(PagingFilter filter)
{
int pos = 0;
//load only start pages intervals margins from both database
//this part need to be transformed in a stored procedure on db one, skip, take to return interval start value for each frame
var framesBordersModel1 = new List<Item>();
dbsetModel_1.OrderBy(x => x.Id).ThenBy(z => z.OrderNumber).ToList().ForEach(i => {
pos++;
if (pos - 1 == 0)
{
framesBordersModel1.Add(new Item() { criteria1 = i.Id, criteria2 = i.OrderNumber, model = i });
}
else if ((pos - 1) % filter.Limit == 0)
{
framesBordersModel1.Add(new Item() { criteria1 = i.Id, criteria2 = i.OrderNumber, model = i });
}
});
pos = 0;
//this part need to be transformed in a stored procedure on db two, skip, take to return interval start value for each frame
var framesBordersModel2 = new List<Item>();
dbsetModel_2.OrderBy(x => x.Id2).ThenBy(z => z.OrderNumber2).ToList().ForEach(i => {
pos++;
if (pos - 1 == 0)
{
framesBordersModel2.Add(new Item() { criteria1 = i.Id2, criteria2 = i.OrderNumber2, model = i });
}
else if ((pos -1) % filter.Limit == 0)
{
framesBordersModel2.Add(new Item() { criteria1 = i.Id2, criteria2 = i.OrderNumber2, model = i });
}
});
//decide where is the position of your cursor based on start margins
//int mainCursor = 0;
int cursor1 = 0;
int cursor2 = 0;
//filter pages start from 1, filter.Page cannot be 0, if indeed you have page 0 change a lil' bit he logic
if (framesBordersModel1.Count + framesBordersModel2.Count < filter.Page) throw new Exception("Out of range");
while ( cursor1 + cursor2 < filter.Page -1)
{
if (framesBordersModel1[cursor1].criteria1 < framesBordersModel2[cursor2].criteria1)
{
cursor1++;
}
else if (framesBordersModel1[cursor1].criteria1 > framesBordersModel2[cursor2].criteria1)
{
cursor2++;
}
//you should't get here case main key sound't be duplicate, annyhow
else
{
if (framesBordersModel1[cursor1].criteria2 < framesBordersModel2[cursor2].criteria2)
{
cursor1++;
}
else
{
cursor2++;
}
}
//mainCursor++;
}
//magic starts
//inpar skipable
int skipEndResult = 0;
List<Item> dbFramesMerged = new List<Item>();
if ((cursor1 + cursor2) %2 == 0)
{
dbFramesMerged.AddRange(
dbsetModel_1.OrderBy(x => x.Id)
.ThenBy(z => z.OrderNumber)
.Skip(cursor1*filter.Limit)
.Take(filter.Limit)
.Select(x => new Item() {criteria1 = x.Id, criteria2 = x.OrderNumber, model = x})
.ToList()); //consider as db call EF or Stored Procedure
dbFramesMerged.AddRange(
dbsetModel_2.OrderBy(x => x.Id2)
.ThenBy(z => z.OrderNumber2)
.Skip(cursor2*filter.Limit)
.Take(filter.Limit)
.Select(x => new Item() {criteria1 = x.Id2, criteria2 = x.OrderNumber2, model = x})
.ToList());
; //consider as db call EF or Stored Procedure
}
else
{
skipEndResult = filter.Limit;
if (cursor1 > cursor2)
{
cursor1--;
}
else
{
cursor2--;
}
dbFramesMerged.AddRange(
dbsetModel_1.OrderBy(x => x.Id)
.ThenBy(z => z.OrderNumber)
.Skip(cursor1 * filter.Limit)
.Take(filter.Limit)
.Select(x => new Item() { criteria1 = x.Id, criteria2 = x.OrderNumber, model = x })
.ToList()); //consider as db call EF or Stored Procedure
dbFramesMerged.AddRange(
dbsetModel_2.OrderBy(x => x.Id2)
.ThenBy(z => z.OrderNumber2)
.Skip(cursor2 * filter.Limit)
.Take(filter.Limit)
.Select(x => new Item() { criteria1 = x.Id2, criteria2 = x.OrderNumber2, model = x })
.ToList());
}
IQueryable<Item> qItems = dbFramesMerged.AsQueryable();
PagedList<Item> result = new PagedList<Item>();
result.AddRange(qItems.OrderBy(x => x.criteria1).ThenBy(z => z.criteria2).Skip(skipEndResult).Take(filter.Limit).ToList());
//here again you need db cals to get total count
result.Total = dbsetModel_1.Count() + dbsetModel_2.Count();
result.Limit = filter.Limit;
result.Page = filter.Page;
return result;
}
}
public class PagingFilter
{
public int Limit { get; set; }
public int Page { get; set; }
}
public class PagedList<T> : List<T>
{
public int Total { get; set; }
public int? Page { get; set; }
public int? Limit { get; set; }
}
public class Item : Criteria
{
public object model { get; set; }
}
public class Criteria
{
public int criteria1 { get; set; }
public int criteria2 { get; set; }
//more criterias if you need to order
}
public class model1
{
public int Id { get; set; }
public int OrderNumber { get; set; }
public string Name { get; set; }
}
public class model2
{
public int Id2 { get; set; }
public int OrderNumber2 { get; set; }
public string Name2 { get; set; }
}
}

Updating nested list values with Linq?

I am trying to update a nested list in C# which looks like this
List<Users>
- UserType
- List<UserComponents>
- - UserComponentKey
- - Count
Here's a written example:
List of users:
UserType = 1
UserComponents
- UserComponentKey = XYZ
- Count = 3
UserType = 2
UserComponents
- UserComponentKey = XYZ
- Count = 7
I need to update UserComponentKey XYZ for UserType 2 only, currently my updates are broken and updates XYZ for all user types. Here is my current methods which do not work as they update the UserComponent count value for ALL usertypes which contain the specified component key, and not the specific usertype I am targeting.
CLASSES:
public class Users
{
public string UserType { get; set; }
public List<UserComponent> UserComponents { get; set; }
}
public class UserComponent
{
public string UserComponentKey { get; set; }
public int Count { get; set; }
}
METHOD 1:
Users.Where(us => us.UserType == "2")
.First().UserComponents
.Where(uc => uc.UserComponentKey == "XYZ")
.First().Count = value;
METHOD 2:
if(users.UserType == "2")
{
foreach(var component in users.UserComponents)
{
switch(component.UserComponentKey)
{
case "XYZ":
component.Count = value;
break;
}
}
}
CODE GENERATING LIST (similar to):
List UserComponents = new List();
if (Item.UserAddOn != null)
{
for (var i = 0; i < Item.UserAddOn.First().Count; i++)
{
UserComponents.Add(new UserComponent
{
UserComponentKey = Item.UserAddOn[i].ComponentKey,
Count = 0
});
}
}
if (Item.User != null)
{
for (var i = 0; i < Item.User.First().Count; i++)
{
Users.Add(new User()
{
UserType = Item.User[i].ComponentKey,
Count = 0,
UsersComponents = UserComponents
});
}
}
I have stripped out actual values etc, but hopefully someone can point me in the right direction here.
Thanks!

I'm missing information to write a snippet you can use so I will simply explain it. An object variable is in reality a reference (a pointer, if you are familiar with C++/C) to the location where the object reside. When you add an object to a list, you add it's location. If you add this object to multiple list, you give the same location and therefor, editing one of them will edit all of them.
var uc1 = new UserComponent { Count = 1 };
var uc2 = new UserComponent { Count = 2 };
var uc3 = new UserComponent { Count = 2 };
var u1 = new User();
var u2 = new User();
u1.UserComponents.Add(uc1);
u1.UserComponents.Add(uc2);
u2.UserComponents.Add(uc1);
u2.UserComponents.Add(uc3);
Console.Write(u1.UserComponents[0].Count); //Outputs 1
Console.Write(u1.UserComponents[1].Count); //Outputs 2
Console.Write(u2.UserComponents[0].Count); //Outputs 1
Console.Write(u2.UserComponents[1].Count); //Outputs 2
u2.UserComponents[0].Count = 5;
u2.UserComponents[1].Count = 6;
Console.Write(u1.UserComponents[0].Count); //Outputs 5
Console.Write(u1.UserComponents[1].Count); //Outputs 6
Console.Write(u2.UserComponents[0].Count); //Outputs 5
Console.Write(u2.UserComponents[1].Count); //Outputs 2
So your code to change values is fine, but when you build up your list, you need to create distinct UserComponents if they are not linked together.

Your first call to First() is wrong. Try it like this:
Users.Where((us) => us.UserType == "2")
.Select((us) => us.UserComponents)
.Where((uc) => uc.UserComponentKey == "XYZ")
.First()
.Count = value;
Suggestion: Why don't you make UserType an int?

May be it helps:
List<Users> _users = new List<Users>();
_users.Add(new Users() { UserType = "1", UserComponents = new List<UserComponent>() { new UserComponent() { Count = 0, UserComponentKey = "XYZ" } } });
_users.Add(new Users() { UserType = "2", UserComponents = new List<UserComponent>() { new UserComponent() { Count = 2, UserComponentKey = "XYZ" } } });
_users.Add(new Users() { UserType = "3", UserComponents = new List<UserComponent>() { new UserComponent() { Count = 5, UserComponentKey = "XYZ" } } });
_users.Where(us => us.UserType == "2").First().UserComponents.Where(uc => uc.UserComponentKey == "XYZ").First().Count = 356;
foreach (Users us in _users)
{
Console.WriteLine("UserType: " + us.UserType);
foreach (UserComponent uc in us.UserComponents)
{
Console.WriteLine("Key: {0} Value: {1}", uc.UserComponentKey, uc.Count);
}
}

Determining value jumps in List<T>

I have a class:
public class ShipmentInformation
{
public string OuterNo { get; set; }
public long Start { get; set; }
public long End { get; set; }
}
I have a List<ShipmentInformation> variable called Results.
I then do:
List<ShipmentInformation> FinalResults = new List<ShipmentInformation>();
var OuterNumbers = Results.GroupBy(x => x.OuterNo);
foreach(var item in OuterNumbers)
{
var orderedData = item.OrderBy(x => x.Start);
ShipmentInformation shipment = new ShipmentInformation();
shipment.OuterNo = item.Key;
shipment.Start = orderedData.First().Start;
shipment.End = orderedData.Last().End;
FinalResults.Add(shipment);
}
The issue I have now is that within each grouped item I have various ShipmentInformation but the Start number may not be sequential by x. x can be 300 or 200 based on a incoming parameter. To illustrate I could have
Start = 1, End = 300
Start = 301, End = 600
Start = 601, End = 900
Start = 1201, End = 1500
Start = 1501, End = 1800
Because I have this jump I cannot use the above loop to create an instance of ShipmentInformation and take the first and last item in orderedData to use their data to populate that instance.
I would like some way of identifying a jump by 300 or 200 and creating an instance of ShipmentInformation to add to FinalResults where the data is sequnetial.
Using the above example I would have 2 instances of ShipmentInformation with a Start of 1 and an End of 900 and another with a Start of 1201 and End of 1800

Try the following:
private static IEnumerable<ShipmentInformation> Compress(IEnumerable<ShipmentInformation> shipments)
{
var orderedData = shipments.OrderBy(s => s.OuterNo).ThenBy(s => s.Start);
using (var enumerator = orderedData.GetEnumerator())
{
ShipmentInformation compressed = null;
while (enumerator.MoveNext())
{
var current = enumerator.Current;
if (compressed == null)
{
compressed = current;
continue;
}
if (compressed.OuterNo != current.OuterNo || compressed.End < current.Start - 1)
{
yield return compressed;
compressed = current;
continue;
}
compressed.End = current.End;
}
if (compressed != null)
{
yield return compressed;
}
}
}
Useable like so:
var finalResults = Results.SelectMany(Compress).ToList();

If you want something that probably has terrible performance and is impossible to understand, but only uses out-of-the box LINQ, I think this might do it.
var orderedData = item.OrderBy(x => x.Start);
orderedData
.SelectMany(x =>
Enumerable
.Range(x.Start, 1 + x.End - x.Start)
.Select(n => new { time = n, info = x))
.Select((x, i) => new { index = i, time = x.time, info = x.info } )
.GroupBy(t => t.time - t.info)
.Select(g => new ShipmentInformation {
OuterNo = g.First().Key,
Start = g.First().Start(),
End = g.Last().End });
My brain hurts.
(Edit for clarity: this just replaces what goes inside your foreach loop. You can make it even more horrible by putting this inside a Select statement to replace the foreach loop, like in rich's answer.)

How about this?
List<ShipmentInfo> si = new List<ShipmentInfo>();
si.Add(new ShipmentInfo(orderedData.First()));
for (int index = 1; index < orderedData.Count(); ++index)
{
if (orderedData.ElementAt(index).Start ==
(si.ElementAt(si.Count() - 1).End + 1))
{
si[si.Count() - 1].End = orderedData.ElementAt(index).End;
}
else
{
si.Add(new ShipmentInfo(orderedData.ElementAt(index)));
}
}
FinalResults.AddRange(si);

Another LINQ solution would be to use the Except extension method.
EDIT: Rewritten in C#, includes composing the missing points back into Ranges:
class Program
{
static void Main(string[] args)
{
Range[] l_ranges = new Range[] {
new Range() { Start = 10, End = 19 },
new Range() { Start = 20, End = 29 },
new Range() { Start = 40, End = 49 },
new Range() { Start = 50, End = 59 }
};
var l_flattenedRanges =
from l_range in l_ranges
from l_point in Enumerable.Range(l_range.Start, 1 + l_range.End - l_range.Start)
select l_point;
var l_min = 0;
var l_max = l_flattenedRanges.Max();
var l_allPoints =
Enumerable.Range(l_min, 1 + l_max - l_min);
var l_missingPoints =
l_allPoints.Except(l_flattenedRanges);
var l_lastRange = new Range() { Start = l_missingPoints.Min(), End = l_missingPoints.Min() };
var l_missingRanges = new List<Range>();
l_missingPoints.ToList<int>().ForEach(delegate(int i)
{
if (i > l_lastRange.End + 1)
{
l_missingRanges.Add(l_lastRange);
l_lastRange = new Range() { Start = i, End = i };
}
else
{
l_lastRange.End = i;
}
});
l_missingRanges.Add(l_lastRange);
foreach (Range l_missingRange in l_missingRanges) {
Console.WriteLine("Start = " + l_missingRange.Start + " End = " + l_missingRange.End);
}
Console.ReadKey(true);
}
}
class Range
{
public int Start { get; set; }
public int End { get; set; }
}