create dictionary occurrences for each letter c# - c#

We have a program that shows you how many times a letter is repeated in a text
string txt = input.text.ToLower();
txt = Regex.Replace(txt, #"\s+", "").Replace(")","").Replace("(","").Replace(".","").Replace(",","").Replace("!","").Replace("?","") ;
var letterCount = txt.Where(char.IsLetter).GroupBy(c => c).Select(v => new { Letter = v.Key, count = v.Count() });
foreach (var c in letterCount)
{
Debug.Log(string.Format("Caracterul:{0} apare {1} ori", c.Letter.ToString(), c.count));
}
And how do I give for the most repeating letter the value of 26, then for the one that repeats the less it gets 25 and for the one that only once a value in alphabetical order?
For example, the text "we are all happy"
Letter A is repeated three times and has the value of 26
For letter L 25
For P 24 and others in alphabetical order
And, finally, get their sum?
Sorry for my English!!!

You can use this LINQ approach:
string input = "we are all happy";
var allCharValues = input.ToLookup(c => c)
.Where(g => g.Key != ' ') // or you want spaces?
.OrderByDescending(g => g.Count())
.ThenBy(g => g.Key) // you mentioned alphabetical ordering if two have same count
.Select((x, index) => new { Char = x.Key, Value = 26 - index, Count = x.Count() });
foreach (var x in allCharValues)
Console.WriteLine($"Char:{x.Char} Value:{x.Value} Count:{x.Count}");
int sum = allCharValues.Select(x => x.Value).Sum();

In relation to your question about removing unwanted characters:
I think you'd be better of just keeping all characters between a and z. You could write an extension method to do this, and convert to lowercase at the same time:
public static class StringExt
{
public static string AlphabeticChars(this string self)
{
var alphabeticChars = self.Select(char.ToLower).Where(c => 'a' <= c && c <= 'z');
return new string(alphabeticChars.ToArray());
}
}
Then you can use an approach as follows. This is similar to Tim's approach, but this uses GroupBy() to count the occurrences; it also uses the new Tuple syntax from C#7 to simplify things. Note that this ALSO names the tuple properties, so they are not using the default Item1 and Item2.
string txt = "we, (are?) all! happy.";
var r = txt
.AlphabeticChars()
.GroupBy(c => c)
.Select(g => (Count: g.Count(), Char: g.Key))
.OrderByDescending(x => x.Count)
.ThenBy(x => x.Char)
.Select((v, i) => (Occurance: v, Index: 26-i));
int sum = r.Sum(c => c.Occurance.Count * c.Index);
Console.WriteLine(sum);

Related

First non-repeated character C# LINQ

I've tried some answers from Stackoverflow but they don't count register of the symbols. For example
sTreSS => T (not 's'),
stress => t
Here is what i tried
public static char FirstNonRepeatedCharacter(string s)
{
var output = s.GroupBy(item => item).First(x => x.Count() == 1).Key;
return output;
}
I need to edit the code with case-insensitive and return the correct register
sEVeraL -> s; - SomeBody - S
This is exactly what you need, but not fully in LINQ. In my opinion, you don't have to strictly rely on LINQ...
Console.WriteLine(FirstNonRepeatedCharacter("sTreSS"));
Console.WriteLine(FirstNonRepeatedCharacter("stress"));
Console.WriteLine(FirstNonRepeatedCharacter("sEVeraL"));
Console.WriteLine(FirstNonRepeatedCharacter("SomeBody"));
Console.WriteLine(FirstNonRepeatedCharacter("AaBbCc"));
Console.ReadKey();
static char? FirstNonRepeatedCharacter(string s)
{
// Gather the count for each character (case insensitive, example: 's' and 'S' is in the same group).
var counts = new Dictionary<char, int>();
foreach (var ch in s.ToLower())
{
counts[ch] = counts.TryGetValue(ch, out var count)
? count + 1
: 1;
}
// Return first character with count 1.
return s.FirstOrDefault(ch => counts[char.ToLower(ch)] == 1);
}
Output is:
T
t
s
S
nothing (null)
You can group by characters as they are, but by processed character:
.GroupBy(c => char.ToLower(c), c => c)
Code:
// either first not repeating character or '\0'
private static char FirstNonRepeatedCharacter(string s) => s
?.GroupBy(c => char.ToLower(c), c => c)
?.FirstOrDefault(g => g.Count() == 1)
?.First()
?? '\0';
Edit: if you want to return string - "...I need to return an empty string..." -, you can group by string while providing required comparer:
private static string FirstNonRepeatedCharacter(string s) => s
?.GroupBy(c => c.ToString(), StringComparer.OrdinalIgnoreCase)
?.FirstOrDefault(g => g.Count() == 1)
?.Key
?? "";

String Operation using Linq

I am trying to convert FOO BAR BAZ to "GPCSC[", "N##" using linq.
I came this close:
var res2 = new String("FOO BAR BAZ ".ToList().Select((x, i) => x = (i % 2 == 0 ? ++x : --x )).ToArray());
which outputs
GNPC#SC#[
I need to split this string into two parts so that my output will be
`"GPCSC[", "N##"`
I couldn't sort it out yet.
Any solution advice on this?
PS: I am looking for simple solution, not bunch of lines of codes
Fiddle Link : https://dotnetfiddle.net/ml8bOC
You might need to use GroupBy:
string str = "GNPC#SC#[";
var groups = str.Select((v, i) => new { Group = i % 3, Ch = v })
.GroupBy(item => item.Group == 1)
.Select(group => string.Join("", group.Select(item => item.Ch)))
.ToList();
// groups: ["GPCSC[", "N##"]

Converting IEnumerable<IEnumerable<T>> to List<string>

I’m trying to convert from this answer the code:
static IEnumerable<IEnumerable<T>> GetKCombs<T>(IEnumerable<T> list, int length) where T : IComparable
{
if (length == 1) return list.Select(t => new T[] { t });
return GetKCombs(list, length - 1)
.SelectMany(t => list.Where(o => o.CompareTo(t.Last()) > 0),
(t1, t2) => t1.Concat(new T[] { t2 }));
}
Into a list of strings. For example I want this output {1,2} {1,3} to convert it to "1,2","1,3" (this is 2 seperate string) but I cant get it. I cant even understand how I can read the results of the above function. this is my code:
int[] numbers = ListEditText.Text.Split(',').Select(x => int.Parse(x)).ToArray();
var combinations = GetKCombs(numbers, 2);
stringCombinations = combinations.Select(j => j.ToString()).Aggregate((x, y) => x + "," + y);
In the end all the results i will add them on a List with all the possible unique combinations
For example for the numbers {1,2,3} i want this List:
'1','2','3','1,2','1,3','2,3','1,2,3'
This is my code right now:
List<string> stringCombinations = new List<string>();
for (int i = 0; i < numbers.Count(); i++)
{
combinations = GetKCombs(numbers, i + 1).Select(c => string.Join(",", c));
stringCombinations.AddRange(combinations);
}
You can try first joining the results of the inner IEnumerables
var combinations = GetKCombs(numbers, 2).Select(c => string.Join(",", c));
and then concatenating them into a single string
var combinationString = string.Join("; ", combinations); // "1,2; 1,3"
Based on your edits -- if I got you right -- you can try doing
var combinationStrings =
numbers
.SelectMany((_, i) =>
GetKCombs(numbers, i + 1) // get combinations for each 'length'
.Select(c => string.Join(",", c))) // join them to a string
.ToList();
Try
var stringCombinations = string.Join(",", combinations.Select(j => $#"""{string.Join(",", j)}"""));
It prints exactly the output you want.

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.

LINQ - Select min count

I have a list of strings which contain X in them. I want to select list(s) with the minimum count of X in them. For example:
CountMin("AXBXX", "AAX") will return AAX.
How can I write this qith LINQ in a concise way ?
public static string CountMin(IList<string> inputList)
{
if (inputList == null || !inputList.Any()) return null;
var result = inputList.Select(s => new
{
Item = s,
Count => s.Count(ch => ch == 'X')
})
.OrderBy(item => item.Count).First().Item;
}
Snippet assumes that all elements on list are different to null. If you need it, it could be easily improved.
You can also omit temporary class:
inputList.OrderBy(s => s.Count(c => c == 'X')).First();
string[] list = {"AXBXX", "AAX", "AXX"};
string result = (from word in list
select new { word, wordLen = (word.Length - (word.Replace("X", "")).Length) })
.OrderBy(x => x.wordLen).First().word;
MessageBox.Show(result);
Here's an answer that will get you all of the minimum X strings from the list.
var listOfStrings = new List<string>()
{
"AXB",
"ABXXC",
"ABX",
};
var minimumXs =
listOfStrings
.GroupBy(x => x.Count(y => y == 'X'))
.OrderBy(x => x.Key)
.Take(1)
.SelectMany(x => x);
That gives me:
AXB
ABX

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