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How to use LINQ to find a sum?

I have this structure:
private readonly Dictionary<string, Dictionary<string, int>> _storage =
new Dictionary<string, Dictionary<string, int>>();
key: Firmware(string): key: Device(string) : value CountOfUsers (int)
I need to get the total of users for each device, but I really don't know how to do it with LINQ. Already tried a lot of variants. Please, help!
For now, I just use a whole function for it
private XlsRow2 GetTotalPerDevice(Dictionary<string, Dictionary<string, int>> storage)
{
XlsRow2 totalPerDeviceRow = new XlsRow2();
totalPerDeviceRow._Name = "Grand Total";
totalPerDeviceRow.UseBorders = true;
foreach (var deviceModel in _allDeviceModels)
{
foreach (var firmware in storage)
{
foreach (var device in firmware.Value)
{
var countOfUsers = 0;
if (deviceModel == device.Key)
{
countOfUsers += device.Value;
if (!_totalsPerDevice.ContainsKey(deviceModel))
{
_totalsPerDevice.Add(deviceModel, countOfUsers);
}
else
{
_totalsPerDevice[deviceModel] += countOfUsers;
}
}
}
}
}
foreach (var deviceModel in _allDeviceModels)
{
if (_totalsPerDevice.ContainsKey(deviceModel))
{
totalPerDeviceRow._AddColumn(_totalsPerDevice.First(k => k.Key == deviceModel.ToString()).Value.ToString());
}
else
{
totalPerDeviceRow._AddColumn("");
}
}
return totalPerDeviceRow;
}

Something like this for example?
var result = _storage.SelectMany(x => x.Value)
.GroupBy(x => x.Key)
.Select(x => new { Device = x.Key, Total = x.Sum(y => y.Value) });

Since the keys for the data that you would like to aggregate is in the second-level dictionary, a good first step would be to dump all key-value pairs from inner dictionaries into a flat sequence. After that all you need is to aggregate the counts, like this:
var res = _storage
.SelectMany(d => d.Value)
.GroupBy(kvp => kvp.Key)
.ToDictionary(g => g.Key, g => g.Sum(kvp => kvp.Value));

A Dictionary implements IEnumerable<KeyValuePair<TKey,TValue> which means you can use LINQ on it. In this case you have a dictionary of dictionaries and need to group by the second level key. To do that, you need to flatten the dictionaries, something that can be done with SelectMany
_storage.Selectmany(pair=>pair.Value);
Once you have the leaf-level entries, you can group by their keys:
_storage.Selectmany(pair=>pair.Value)
.GroupBy(leaf=>leaf.Key);
And calculate the sum per group:
var totals=_storage.SelectMany(pair=>pair.Value)
.GroupBy(leaf=>leaf.Key)
.Select(grp=>new {
Device = grp.Key,
TotalUsers =grp.Sum(leaf=>leaf.Value)
});
The equivalent query is rather cleaner:
var totals2 = from frm in _storage
from dev in frm.Value
group dev by dev.Key into grp
select new {
Device = grp.Key,
Total=grp.Sum(leaf=>leaf.Value)
};
Given the following dictionary:
var _storage = new Dictionary<string, Dictionary<string, int>> {
["Frm1"]=new Dictionary<string, int> {
["Device1"]=4,
["Device2"]=5
},
["Frm2"]=new Dictionary<string, int> {
["Device1"]=41,
["Device3"]=5
}
};
Both queries return the same values
foreach(var total in totals)
{
Console.WriteLine ($"{total.Device} = {total.Total}");
}
------------------
Device1 = 45
Device2 = 5
Device3 = 5

You can do this like:
Dictionary<string, Dictionary<string, int>> _storage = new Dictionary<string, Dictionary<string, int>>();
Dictionary<string, int> x = new Dictionary<string, int>();
x.Add("x", 2);
x.Add("z", 2);
x.Add("y", 2);
_storage.Add("x", x);
_storage.Add("z", x);
_storage.Add("y", x);
var b = _storage.SelectMany(keyValuePair => keyValuePair.Value)
.GroupBy(keyValuePair => keyValuePair.Key)
.ToDictionary(valuePairs => valuePairs.Key, grouping => grouping.Sum(kvp => kvp.Value));
result will be like:

split string to Dictionnary<string, int>

I have a string like that : "content;123 contents;456 contentss;789 " etc..
I would like to split this string to get a Dictionary, but I don't know you to make it. I try to split the string but I got a List only.
The content (before semi colon) is always a unique string.
After the semi colon, I always have a number until I found the space.
the number is always an int (no float needs).
Could someone help me please ?

You can use the following LINQ expression:
"content;123 contents;456 contentss;789"
.Split(' ')
.Select(x => x.Split(';'))
.ToDictionary(x => x[0], x => int.Parse(x[1]));

string input = "content1;123 content2;456 content3;789";
var dict = Regex.Matches(input, #"(.+?);(\d+)").Cast<Match>()
.ToDictionary(m => m.Groups[1].Value, m => int.Parse(m.Groups[2].Value));

You can do something like this:
string value = "content;123 contents;456 contentss;789";
Dictionary<string, int> data = new Dictionary<string,int>();
foreach(string line in value.Split(' '))
{
string[] values = line.Split(';');
if (!data.ContainsKey(values[0]))
{
data.Add(values[0], Convert.ToInt32(values[1]));
}
}

var myList = "content1;number1 content2;number2 content3;number3";
var myDictionary = myList.Split(' ').Select(pair => pair.Split(';')).ToDictionary(splitPair => splitPair[0], splitPair => int.Parse(splitPair[1]));

static void Main(string[] args)
{
string content = "content;123 contents;456 contentss;789";
Dictionary<string, int> result = new Dictionary<string, int>();
content.Split(' ').ToList().ForEach(x =>
{
var items = x.Split(';');
result.Add(items[0], int.Parse(items[1]));
});
foreach(var item in result)
{
Console.WriteLine("{0} -> {1}" , item.Key, item.Value);
}
}

Search in dictionary of dictionaries

I have a dictionary defined as seen here:
Dictionary<int, Dictionary<string, object>> dict = new Dictionary<..>();
And a sample code for adding data:
dict.Add (X, new Dictionary<string, object> ());
dict [X].Add ("Car", CarObject);
dict [X].Add ("Seller", SellerObject);
dict [X].Add ("Key3", Z);
I want to search in the inner dictionary if it contains an object which then contains the following
CarObject.Name = (wildcard)X1(wildcard) of the key "Car" but I just can't seem to get a grasp of how to get into the inner dictionary and then into the object with LINQ in order to search for the value.

This will return all matching KeyValuePair<string, object>.
var query = dict.SelectMany(d => d.Value)
.Where(i => i.Key == "Key1"
&& (
i.Value is CarObject
? ((CarObject)i.Value).Name.Contains("X1")
: false
));

Try the following:
var results = dict[X].Where(x => (x.Value is CarObject) && ((CarObject)x.Value).Name.Contains("X1"));
If you want to get just the value and not the dictionary, and print the values, you can do this:
int X = 0, Z = 1;
dict[X].Add("Key1", CarObject);
dict[X].Add("Key2", SellerObject);
dict[X].Add("Key3", Z);
var results = dict[X].Where(x => (x.Value is CarObject) && ((CarObject)x.Value).Name.Contains("X1")).Select(x => x.Value);
foreach (var str in results)
Console.WriteLine(str);

You can try something like:
dict[X].Where(x => x.Value is CarObject && ((CarObject)x.Value).Name.Contains("X1"));
Or:
dict[X].Values.OfType<CarObject>().Any(x => x.Name.Contains("X1"))

Join two dictionaries by value diffs

I have these two dictionaries:
Dictionary<char, double> analyzed_symbols = new Dictionary<char, double>();
Dictionary<char, double> decode_symbols = new Dictionary<char, double>();
I need to create another dictionary that should have their keys as key and value, like this:
Dictionary<char, char> replace_symbols = new Dictionary<char, char>();
The condition to "join" them is that difference between values should be minimal, like this:
Math.Min(Math.Abs(analyzed_symbols[key] - decode_symbols[key]))
I guess I should use LINQ for this purpose but can't figure out how to write query properly.
Data Sample:
analyzed_symbols = [a, 173], [b, 1522], [z, 99]
decode_symbols = [в, 100], [д, 185], [e, 1622]
For these dicts output data should look like this:
replace_symbols = [z, в], [b, е], [a, д]
I've found question that is pretty close to what I need, but not exactly. Snowy asks there about one close value, but I need to do the same thing for two dictionaries.

This is my take on it:
var analyzed_symbols = new Dictionary<char, double>(){ {'a', 173}, {'b', 1522}, {'z', 99} };
var decode_symbols = new Dictionary<char, double>(){ {'в', 100}, {'д', 185}, {'e', 1622} };
var q = from a in analyzed_symbols
from d in decode_symbols
let tmp = new { A = a.Key, D = d.Key, Value = Math.Abs(a.Value - d.Value) }
group tmp by tmp.A into g
select new
{
Key = g.Key,
Value = g.OrderBy (x => x.Value).Select (x => x.D).First()
};
var replace_symbols = q.ToDictionary (x => x.Key, x => x.Value);

Okay, I'll try. I divided into several queries, because it's more readable that way.
//sorting values of the dictionaries to easily get closest
var analyzedSortedValues = analyzed_symbols.Values.OrderBy(k => k);
var decodeSortedValues = decode_symbols.Values.OrderBy(k => k);
//creating pairs of the closest values. Here I use iterator index i to skip
//some values that have been used already (is it correct?)
var t = analyzedSortedValues.Select((k, i) => new { a = k, d = decodeSortedValues.Skip(i).Any() ? decodeSortedValues.Skip(i).First() : -1 });
//printing results by getting appropriate keys from corresponding dictionaries
foreach (var item in t)
{
Console.WriteLine("[{0}, {1}]", analyzed_symbols.FirstOrDefault(kvp => kvp.Value == item.a).Key, decode_symbols.FirstOrDefault(kvp => kvp.Value == item.d).Key);
}

I am not exactly sure how to do it via LINQ but here is the longhand version of what you want to do.
private static Dictionary<char, char> BuildReplacementDictionary(Dictionary<char, double> analyzedSymbols,
Dictionary<char, double> decodeSymbols)
{
Dictionary<char, char> replaceSymbols = new Dictionary<char, char>(analyzedSymbols.Count);
foreach (KeyValuePair<char, double> analyzedKvp in analyzedSymbols)
{
double bestMatchValue = double.MaxValue;
foreach (KeyValuePair<char, double> decodeKvp in decodeSymbols)
{
var testValue = Math.Abs(analyzedKvp.Value - decodeKvp.Value);
if (testValue <= bestMatchValue)
{
bestMatchValue = testValue;
replaceSymbols[analyzedKvp.Key] = decodeKvp.Key;
}
}
}
return replaceSymbols;
}
What it does is it goes through each element of the analyzed dictionary, test every element of the decoded dictionary, and if that match is the same or better than the previous match it found it will use the new value from the decoded dictionary.

How to convert List<String> to Dictionary<int,String>

I have List<String>, i need to convert it to Dictionary<int,String> with auto generation of Key, is any shortest way to accomplish that? I have tried:
var dictionary = new Dictionary<int, String>();
int index = 0;
list.ForEach(x=>{
definitions.Add(index, x);
index++;
});
but i think it is dirty way.

var dict = list.Select((s, i) => new { s, i }).ToDictionary(x => x.i, x => x.s);

I find this to be the neatest
int index = 0;
var dictionary = myList.ToDictionary(item => index++);

In my opinion, what you have is more readable than the Linq way (and as a bonus, it happens to be more efficient):
foreach(var item in list)
dictionary[index++] = item;

Use:
var dict = list.Select((x, i) => new {x, i})
.ToDictionary(a => a.i, a => a.x);