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Looking for next match (integer) in list of strings

I have a problem finding the next integer match in a list of strings, there are some other aspects to consider:
single string contains non relevant trailing and leading chars
numbers are formatted "D6" example 000042
there are gaps in the numbers
the list is not sorted, but it could be if there is a fast way to ignore the leading chars
Example:
abc-000001.file
aaac-000002.file
ab-002010.file
abbc-00003.file
abbbc-00004.file
abcd-00008.file
abc-000010.file
x-902010.file
The user input is 7 => next matching string would be abcd-000008.file
My attempt is :
int userInput = 0;
int counter = 0;
string found = String.Empty;
bool run = true;
while (run)
{
for (int i = 0; i < strList.Count; i++)
{
if(strList[i].Contains((userInput + counter).ToString("D6")))
{
found = strList[i];
run = false;
break;
}
}
counter++;
}
It's bad because it's slow and it can turn into a infinite loop. But I really don't know how to do this (fast).

You can parse numbers from strings with Regex and created a sorted collection which you can search with Where clause:
var strings = new[] { "abc-000001.file", "x-000004.file"};
var regP = "\\d{6}"; // simplest option in my example, maybe something more complicated will be needed
var reg = new Regex(regP);
var collection = strings
.Select(s =>
{
var num = reg.Match(s).Captures.First().Value;
return new { num = int.Parse(num), str = s};
})
.OrderBy(arg => arg.num)
.ToList();
var userInput = 2;
var res = collection
.Where(arg => arg.num >= userInput)
.FirstOrDefault()?.str; // x-000004.file
P.S.
How 9002010, 0000010, 0002010 should be treated? Cause they have 7 characters. Is it [9002010, 10, 2010] or [900201, 1, 201]?

If you don't want regex, you can do something like that:
List<string> strings = new List<string>
{
"abc-000001.file",
"aaac-000002.file",
"ab-0002010.file",
"abbc-000003.file",
"abbbc-000004.file",
"abcd-000008.file"
};
int input = 7;
var converted = strings.Select(s => new { value = Int32.Parse(s.Split('-', '.')[1]), str = s })
.OrderBy(c => c.value);
string result = converted.FirstOrDefault(v => v.value >= input)?.str;
Console.WriteLine(result);

how to arrange the item of a list into series arrangement

I have a list of data which contains of random data with combination of string and number:
List<String> Data1 = new List<String>()
{
"1001A",
"1002A",
"1003A",
"1004A",
"1015A",
"1016A",
"1007A",
"1008A",
"1009A",
};
I want this data to arrange into series like this:
1001A - 1004A, 1007A - 1009A, 1015A, 1016A
for every more than 2 counts of data series the output shall be have "-" between the first count and the last count of series, the other non series data will be just added to the last part and all together will separated by ",".
I'd already made some codes only to arrange the data series by the last char of it:
string get_REVISIONMARK = "A";
var raw_serries = arrange_REVISIONSERIES.Where(p => p[p.Length - 1].ToString() == get_REVISIONMARK) .OrderBy(p => p[p.Length - 1) .ThenBy(p => p.Substring(0, p.Length - 1)).ToList();
just ignore the last char I'd already have function for that, and my problem only about the arrangement of the numbers, the length of data is not fixed. for other example of output "1001A - 1005A, 301A, 32A"
I had another sample of my codes this works fine to me, but for me its so lazy code.
for (int c1 = 0; c1 < list_num.Count; c1++)
{
if (list_num[c1] != 0)
{
check1 = list_num[c1];
for (int c2 = 0; c2 < list_num.Count; c2++)
{
if (check1 == list_num[c2])
{
list_num[c2] = 0;
check1 += 1;
list_series.Add(arrange_REVISIONSERIES[c2]);
}
}
check1 = 0;
if (list_series.Count > 2)
{
res_series.Add(list_series[0] + " to " +list_series[list_series.Count - 1]);
list_series.Clear();
}
else
{
if (list_series.Count == 1)
{
res_series.Add(list_series[0]);
list_series.Clear();
}
else
{
res_series.Add(list_series[0] + "," + list_series[1]);
list_series.Clear();
}
}
}
}
var combine_res = String.Join(",", res_series);
MessageBox.Show(combine_res);
this codes work fine for the series number ...

A possible solution (working with current set of values), Please follow the steps below
Declare a class level string list as
public List<String> data_result = new List<string>();
Create a function to iterate through input string list (input string declared inside, named 'data')
public void ArrangeList()
{
List<String> data = new List<string>() { "1001A", "1002A", "1003A",
"1004A", "1015A", "1016A", "1007A", "1008A", "1009A", "1017A" };
List<int> data_int = data.Select(a => Convert.ToInt32(a.Substring(0,
a.Length - 1))).OrderBy(b => b).ToList();
int initializer = 0, counter = 0;
int finalizer = 0;
foreach (var item in data_int)
{
if (initializer == 0)
{ initializer = item; continue; }
else
{
counter++;
if (item == initializer + counter)
finalizer = item;
else
{
LogListing(initializer, finalizer);
initializer = item;
finalizer = item;
counter = 0;
}
}
}
LogListing(initializer, finalizer);
}
Create a function which just logs the result into data_result string list.
public void LogListing(int initializer, int finalizer)
{
if (initializer != finalizer)
{
if (finalizer == initializer + 1)
{
data_result.Add(initializer + "A");
data_result.Add(finalizer + "A");
}
else
data_result.Add(initializer + "A - " + finalizer + "A");
}
else
data_result.Add(initializer + "A");
}
It perfectly generates the result list as
Thumb-up if you like

A linqy solution:
char get_REVISIONMARK = 'A';
var res = arrange_REVISIONSERIES.Select(s => new { Rev = s[s.Length - 1], Value = int.Parse(s.Substring(0, s.Length - 1)), Org = s })
.Where(d => d.Rev == get_REVISIONMARK).OrderBy(d => d.Value)
.Select((val, ind) => new { Index = ind, Org = val.Org, Value = val.Value }).GroupBy(a => a.Value - a.Index)
.Select(gr=>gr.ToList()).OrderBy(l=>l.Count > 2 ? 0 : 1 ).Aggregate(new List<string>(), (list, sublist) =>
{
if (sublist.Count > 2)
list.Add(sublist[0].Org + " - " + sublist[sublist.Count - 1].Org);
else
list.AddRange(sublist.Select(a => a.Org));
return list;
});
The first lines are basically the same as the code you already have (filter on revision and sort), but with the difference that the subvalues are stored in an anonymous type. You could do the same on the pre ordered list, but since splitting the string would be done twice I've included it in the total.
Then a select with index (.Select((val, ind) =>) is made to get value/index pairs. This is done to be able to get the sequences based on an old t-sql row_number trick: for each 'group' the difference between value and index is the same .GroupBy(a => a.Value - a.Index)
After that, normally you'd be as good as done, but since you only want to make sequences of 2 and longer, we make sublists out of the groupby values and do the ordering beforehand to make sure the ranges come for the eventual single elements .Select(gr=>gr.ToList()).OrderBy(l=>l.Count > 2 ? 0 : 1 )
Finally, the list is created of the groups. Several options, but I like to use Aggregate for that. The seed is the resulting list, and the aggregate simply adds to that (where subranges > 2 are cummulated and for single elements and pairs, the single elements are added)

I'm making two assumptions:
The list is already ordered
The non-numeric characters can be ignored
You will get the results in the results variable:
void Main()
{
List<String> Data1 = new List<String>()
{
"1001A",
"1002A",
"1003A",
"1004A",
"1015A",
"1016A",
"1007A",
"1008A",
"1009A",
};
var accu = new List<List<Tuple<int, string>>>();
foreach (var data in Data1)
{
if (accu.Any(t => t.Any(d => d.Item1 == (ToInt(data) - 1))))
{
var item = accu.First(t => t.Any(d => d.Item1 == (ToInt(data) - 1)));
item.Add(new Tuple<int, string>(ToInt(data), data));
}
else
{
accu.Add(new List<Tuple<int, string>>{ new Tuple <int, string>(ToInt(data), data)});
}
}
var results = new List<string>();
results.AddRange(accu.Where(g => g.Count > 2).Select(g => string.Format("{0} - {1}", g.First().Item2, g.Last().Item2)));
results.AddRange(accu.Where(g => g.Count <= 2).Aggregate(new List<string>(), (total, current) => { total.AddRange(current.Select(i => i.Item2)); return total; } ));
}
private static Regex digitsOnly = new Regex(#"[^\d]");
public static int ToInt(string literal)
{
int i;
int.TryParse(digitsOnly.Replace(literal, ""), out i);
return i;
}

So given your starting data:
List<String> arrange_REVISIONSERIES = new List<String>()
{
"1001A",
"1002A",
"1003A",
"1004A",
"1015A",
"1016A",
"1007A",
"1008A",
"1009A",
};
I do this first:
var splits =
arrange_REVISIONSERIES
.Select(datum => new
{
value = int.Parse(datum.Substring(0, datum.Length - 1)),
suffix = datum.Substring(datum.Length - 1, 1),
})
.OrderBy(split => split.suffix)
.ThenBy(split => split.value)
.ToArray();
That's basically the same as your raw_serries, but orders the number part as a number. It seems to me that you need it as a number to make the range part work.
I then do this to compute the groupings:
var results =
splits
.Skip(1)
.Aggregate(
new[]
{
new
{
start = splits[0].value,
end = splits[0].value,
suffix = splits[0].suffix
}
}.ToList(),
(a, s) =>
{
if (a.Last().suffix == s.suffix && a.Last().end + 1 == s.value)
{
a[a.Count - 1] = new
{
start = a.Last().start,
end = s.value,
suffix = s.suffix
};
}
else
{
a.Add(new
{
start = s.value,
end = s.value,
suffix = s.suffix
});
}
return a;
})
.Select(r => r.start == r.end
? String.Format("{0}{1}", r.end, r.suffix)
: (r.start + 1 == r.end
? String.Format("{0}{2}, {1}{2}", r.start, r.end, r.suffix)
: String.Format("{0}{2} - {1}{2}", r.start, r.end, r.suffix)))
.ToArray();
And finally, this to create a single string:
var result = String.Join(", ", results);
That gives me:
1001A - 1004A, 1007A - 1009A, 1015A, 1016A
This code nicely works with data containing different suffixes.

How to find maximum number of repeated string in a string in a list of string in c#

If we have a list of strings, then how we can find the list of strings that have the maximum number of repeated symbol by using LINQ.
List <string> mylist=new List <string>();
mylist.Add("%1");
mylist.Add("%136%250%3"); //s0
mylist.Add("%1%5%20%1%10%50%8%3"); // s1
mylist.Add("%4%255%20%1%14%50%8%4"); // s2
string symbol="%";
List <string> List_has_MAX_num_of_symbol= mylist.OrderByDescending(s => s.Length ==max_num_of(symbol)).ToList();
//the result should be a list of s1 + s2 since they have **8** repeated '%'
I tried
var longest = mylist.Where(s => s.Length == mylist.Max(m => m.Length)) ;
this gives me only one string not both

Here's a very simple solution, but not exactly efficient. Every element has the Count operation performed twice...
List<string> mylist = new List<string>();
mylist.Add("%1");
mylist.Add("%136%250%3"); //s0
mylist.Add("%1%5%20%1%10%50%8%3"); // s1
mylist.Add("%4%255%20%1%14%50%8%4"); // s2
char symbol = '%';
var maxRepeat = mylist.Max(item => item.Count(c => c == symbol));
var longest = mylist.Where(item => item.Count(c => c == symbol) == maxRepeat);
It will return 2 strings:
"%1%5%20%1%10%50%8%3"
"%4%255%20%1%14%50%8%4"

Here is an implementation that depends upon SortedDictionary<,> to get what you're after.
var mylist = new List<string> {"%1", "%136%250%3", "%1%5%20%1%10%50%8%3", "%4%255%20%1%14%50%8%4"};
var mappedValues = new SortedDictionary<int, IList<string>>();
mylist.ForEach(str =>
{
var count = str.Count(c => c == '%');
if (mappedValues.ContainsKey(count))
{
mappedValues[count].Add(str);
}
else
{
mappedValues[count] = new List<string> { str };
}
});
// output to validate output
foreach (var str in mappedValues.Last().Value)
{
Console.WriteLine(str);
}
Here's one using LINQ that gets the result you're after.
var result = (from str in mylist
group str by str.Count(c => c == '%')
into g
let max = (from gKey in g select g.Key).Max()
select new
{
Count = max,
List = (from str2 in g select str2)
}).LastOrDefault();

OK, here's my answer:
char symbol = '%';
var recs = mylist.Select(s => new { Str = s, Count = s.Count(c => c == symbol) });
var maxCount = recs.Max(x => x.Count);
var longest = recs.Where(x => x.Count == maxCount).Select(x => x.Str).ToList();
It is complicated because it has three lines (the char symbol = '%'; line excluded), but it counts each string only once. EZI's answer has only two lines, but it is complicated because it counts each string twice. If you really want a one-liner, here it is:
var longest = mylist.Where(x => x.Count(c => c == symbol) == mylist.Max(y => y.Count(c => c == symbol))).ToList();
but it counts each string many times. You can choose whatever complexity you want.

We can't assume that the % is always going to be the most repeated character in your list. First, we have to determine what character appears the most in an individual string for each string.
Once we have the character and it maximum occurrence, we can apply Linq to the List<string> and grab the strings that contain the character equal to its max occurrence.
using System;
using System.Collections.Generic;
using System.Linq;
public class Program
{
public static void Main()
{
List <string> mylist=new List <string>();
mylist.Add("%1");
mylist.Add("%136%250%3");
mylist.Add("%1%5%20%1%10%50%8%3");
mylist.Add("%4%255%20%1%14%50%8%4");
// Determine what character appears most in a single string in the list
char maxCharacter = ' ';
int maxCount = 0;
foreach (string item in mylist)
{
// Get the max occurrence of each character
int max = item.Max(m => item.Count(c => c == m));
if (max > maxCount)
{
maxCount = max;
// Store the character whose occurrence equals the max
maxCharacter = item.Select(c => c).Where(c => item.Count(i => i == c) == max).First();
}
}
// Print the strings containing the max character
mylist.Where(item => item.Count(c => c == maxCharacter) == maxCount)
.ToList().ForEach(Console.WriteLine);
}
}
Results:
%1%5%20%1%10%50%8%3
%4%255%20%1%14%50%8%4
Fiddle Demo

var newList = myList.maxBy(x=>x.Count(y=>y.Equals('%'))).ToList();
This should work. Please correct syntax if wrong anywhere and update here too if it works for you.

last integer in a string in linq

I have a list containing integer or string-integer
like this
TagNo FTerminal
1000 1
1000 5
1000 2S6
how can i get the result like this
TagNo FTerminal
1000 1
5
6
I have this , but definately it gives me error on 2s6.
how can i change it to cover all?
var terminalList = sourceLists.Where(t => t.TagNo == tagList)
.Where(t=>t.FromTerminal.Length>0)
.Select(t => int.Parse(t.FromTerminal))
.OrderBy(t=>t)
.ToList();

Instead of using int.Parse in your LINQ statement, you need to write your own function.
Something like this:
int parseTerminal(string input) {
int result = -1;
if (!int.TryParse(input, out result)) {
result = -99;
}
return result;
}
That would make your LINQ to
var terminalList = sourceLists
.Where( t => t.TagNo == tagList && t.FromTerminal.Length > 0 )
.Select( t => parseTerminak(t.FromTerminal) )
.OrderBy( t=>t )
.ToList();
Result:
TagNo FTerminal
1000 -99
1
5
You need to handle the special case where FromTerminal is not a number yourself.
A naive implementation of the requirement one could think of is something like this:
int parseTerminal(string input) {
int result = -1;
if (!int.TryParse(input, out result)) {
var temporaryString = string.Empty;
var lastInt = -1;
input.ToList().ForEach( aChar => {
if ( aChar >= '0' && aChar <= '9' ) {
temporaryString += aChar;
} else {
if ( temporaryString.Length >= 0 ) {
int.TryParse( temporaryString, out lastInt );
temporaryString = string.Empty;
}
}
} );
if ( temporaryString.Length >= 0 ) {
if (!int.TryParse( temporaryString, out lastInt )) {
lastInt = -98;
}
}
result = lastInt;
}
return result;
}
Note: I would not consider this production ready and you should think about edge cases.

Without knowing much about your data structure I have written a code using some system types.
var tuples = new List<Tuple<int, string>>
{
new Tuple<int, string>(1000, "1"),
new Tuple<int, string>(1000, "5"),
new Tuple<int, string>(1000,"2s6")
};
var enumerable = tuples.GroupBy(t => t.Item1).
Select(g => new Tuple<int, List<int>>(g.Key, g.Select(e => int.Parse(Regex.Match(e.Item2, #"(?<=(\D|^))\d+(?=\D*$)").Value)).ToList()));

The error occurs because you try to handle the string '2S6' as an integer, using int.Parse. This would naturally cause an exception.
I would suggest following another approach, using regular expressions. I think regular expressions are better solution since the data you ask come after string manipulation of the already retrieved query results.
Using regular expressions to do this kind of staff, would make it also easier for you to maintain in the future. Think of the case, that in a week you don't want to retrieve the last digit of the string, but the second digit of the string.
You can use this online regular expression tester to test your regular expression. I suppose the regular expression \d(?!.*\d) would be a good choice, since it returns the last digit.
This article is a good guide in using regular expressions in .NET, including examples.
Hope I helped!

if last symbol always is int you may change your code like this
var terminalList = sourceLists.Where(t => t.TagNo == tagList)
.Where(t=>t.FromTerminal.Length>0)
.Select(t => int.Parse(t.FromTerminal.Last()))
.OrderBy(t=>t)
.ToList();
UPDATE
if last not only one numer that can use regex like this
var terminalList = sourceLists.Where(t => t.TagNo == tagList)
.Where(t=>t.FromTerminal.Length>0)
.Select(t => int.Parse(Regex.Match(t.FromTerminal, #"(\d+)$").Groups[1].Value))
.OrderBy(t=>t)
.ToList();

I am quiet confused what do you wants ... as your picture says you wants the combination of TagNO and FTerminal and in the other hand your query says you wants only FTerminals in certain order ..
Now if you wants the first one then
void Abc(int tagList)
{
var sourceLists = new List<Demo>
{
new Demo { FTerminal = "200", TagNo = 1000 },
new Demo { FTerminal = "300", TagNo = 1000 },
new Demo { FTerminal = "400", TagNo = 1000 }
};
var terminalList = sourceLists
.Where(t => t.TagNo == tagList && t.FTerminal.Length > 0)
.OrderBy(i=>i.FTerminal).GroupBy(i=>i.TagNo);
}
And the second one
void Abc(int tagList)
{
var sourceLists = new List<Demo>
{
new Demo { FTerminal = "200", TagNo = 1000 },
new Demo { FTerminal = "300", TagNo = 1000 },
new Demo { FTerminal = "400", TagNo = 1000 }
};
var terminalList =
from Demo d in sourceLists
where d.TagNo == tagList
let number = int.Parse(d.FTerminal)
orderby number ascending
select number).ToList();
}
But till if you did not get the your desired answer then please knock!!!!

Hmm ... instead of jumping through hoops, just use IsInt ... problem solved ...
:)
var terminalList = sourceLists.Where(t => t.TagNo == tagList)
.Where(t=>t.FromTerminal.Length>0)
.Where(t => t.FromTerminal.IsInt() )
.Select(t => int.Parse(t.FromTerminal))
.OrderBy(t=>t)
.ToList();
(So, just added this condition .Where(t => t.FromTerminal.IsInt() ) to your selection process)

Int.Parse and Sorting

I have the following code..
var strings = new[] {
"FD1","FD5","FD10","FD102","FD105","FD10","FD32","FD80", "FD31", "FD21", "FDnon"
};
strings = strings.Select(str => new
{
str,
num = int.Parse(String.Concat(str.Trim('F', 'D'))),
})
.OrderBy(x => x.num)
.Select(x => x.str)
.ToArray();
However this fails when it gets to "FDnon" as there are no numbers in it,
How do I get this to work with "FDnon" sorted at the top?

var result = strings.OrderBy(x =>
{
int y = int.MinValue;
int.TryParse(x.Substring(2), out y);
return y;
});

If you want custom ordering, supply your custom SortMethod
var sorted = strings
.OrderBy(SpecialSort)
.ToList();
public static int SpecialSort(string value)
{
int sortOrder = 0;
string numberPart = value.Trim('F', 'D');
int.TryParse(numberPart, out sortOrder);
return sortOrder;
}
Edit: Changed solution to account for the sorting of numbers in String.

If you want FDnon to be presented at the top you can use something like:
strings = strings.Select(str => new
{
str,
num = str=="FDnon" ? Int32.MaxValue : Int32.Parse(String.Concat(str.Trim('F', 'D')))
})
.OrderBy(x => x.num)
.Select(x => x.str)
.ToArray();
This code just skips FDnon conversion. If you want to allow other values you should be more specific on what are you going to accept.

You need a more sophisticated parse that converts FDnon into an integral value that will sort last (in this case Int32.MaxValue would do).
Something like:
var res = strings.Select(s => {
var numPart = s.Trim('F', 'D');
var i;
if (!Int32.TryParse(numPart, out i)) {
i = Int32.MaxValue;
}
return new {
str = s,
num = i
};
}.OrderBy …

If the strings always start with two letters, you could also use Substring(2). To check if there's a numeric part, you can use Enumerable.All(Char.IsDigit) (assumes that all chars are digits after the first two lewtters):
strings = strings.Select(str => new
{
str,
num = str.Substring(2).All(Char.IsDigit) ? int.Parse(str.Substring(2)) : int.MinValue
})
.OrderBy(x => x.num)
.Select(x => x.str)
.ToArray();
DEMO