Delete part of string value - c#

I want to mix 2 string in 1 randomly using foreach but I don't know how I delete the part I used on the string for the foreach like:
string s = "idontknow";
string sNew = "";
foreach(char ss in s){
s = s + ss;
ss.Delete(s); //don't exist
}
Full code here i'm trying to do:
do
{
if (state == 0)
{
for (int i = 0; random.Next(1, 5) > variable.Length; i++)
{
foreach (char ch in variable)
{
fullString = fullString + ch;
}
}
state++;
}
else if (state == 1)
{
for (int i = 0; random.Next(1, 5) > numbers.Length; i++)
{
foreach (char n in numbers)
{
fullString = fullString + n;
}
}
state--;
}
} while (variable.Length != 0 && numbers.Length != 0);

I'm pretty confident, that in your first code snippet, you are creating an infinite loop, since you are appending the used char back to the string while removing it from the first position.
Regarding your specification to shuffle two stings together, this code sample might do the job:
public static string ShuffleStrings(string s1, string s2){
List<char> charPool = new();
foreach (char c in s1) {
charPool.Add(c);
}
foreach (char c in s2) {
charPool.Add(c);
}
Random rand = new();
char[] output = new char[charPool.Count];
for(int i = 0; i < output.Length; i++) {
int randomIndex = rand.Next(0, charPool.Count);
output[i] = charPool[randomIndex];
charPool.RemoveAt(randomIndex);
}
return new string(output);
}
In case you just want to shuffle one string into another string, just use an empty string as the first or second parameter.
Example:
string shuffled = ShuffleStrings("TEST", "string");
Console.WriteLine(shuffled);
// Output:
// EgsTtSnrTi
There are possibly other solutions, which are much shorter, but I think this code is pretty easy to read and understand.
Concerning the performance, the code above should works both for small stings and large strings.
Since strings are immutable, each modify-operation on any string, e.g. "te" + "st" or "test".Replace("t", ""), will allocate and create a new string in the memory, which is - in a large scale - pretty bad.
For that very reason, I initialized a char array, which will then be filled.
Alternatively, you can use:
using System.Text;
StringBuilder sb = new();
// append each randomly picked char
sb.Append(c);
// Create a string from appended chars
sb.ToString();
And if your question was just how to remove the first char of a string:
string myStr = "Test";
foreach (char c in myStr) {
// do with c whatever you want
myStr = myStr[1..]; // assign a substring exluding first char (start at index 1)
Console.WriteLine($"c = {c}; myStr = {myStr}");
}
// Output:
// c = T; myStr = est
// c = e; myStr = st
// c = s; myStr = t
// c = t; myStr =

Related

Calculate number of zeros in a string

I have a string as follow 51200000000000000000000000000000
This string is not fixed. It will be appended depends on the number of boards. If there are two boards, the string will be as follow 5120000000000000000000000000000052200000000000000000000000000000
I would like to know how to calculate the number of zeros in the string.
I'm using the following code but it is not flexible if there are more than two boards.
string str = "51200000000000000000000000000000";
string zeros = "00000000000000000000000000000";
if (str.Contains(zeros))
{
Console.WriteLine("true");
}
else
{
Console.WriteLine("false");
}
You can use the following piece of code to do this, which will give you the number of zeros(Example).
char matchChar='0';
string strInput = "51200000000000000000000000000000";
int zeroCount = strInput.Count(x => x == matchChar); // will be 29
You can do the same by iterating through each characters and check whether it is the required character(say 0) then take its count.
Use a simple foreach loop to traverse the string and count:
int CountZeroes(string str)
{
// TODO: error checking, etc.
int count = 0;
foreach (var character in str)
{
if (character == '0') count++;
}
return count;
}
a little advanced (or so) technique would be to convert the string to char array then to list of chars then using LINQ
string str = "51200000000000000000000000000000";
List<char> nums = str.ToCharArray().ToList();
Console.WriteLine(nums.Where(x => x.Equals('0')).Select(x => x.ToString()).Count());
i just placed this here in case you want to learn not just a single approach :)
It can also do with a for loop and Substring.
Code
string str = "51200000000000000000000000000000";
int n = 0;
for (int i = 0; i < str.Length; i++)
{
if (str.Substring(i, 1) == "0")
n += 1;
}
Console.WriteLine("Count : " + n.ToString());
Working fiddle demo
Code:
string st;
st = textBox1.Text;
int countch = 0, i;
for (i = 0; i < st.Length; i++)
if (st[i]=='0') countch++;
MessageBox.Show(countch.ToString());
using System.Linq
int count0s = str.Count(z => z == '0');
will return how many 0's in your str string

C# Guessing Game using a text file

I'm trying to create a word guessing game that uses a dictionary text file. The game is supposed to take input from the user on how long the word should be before asking them to guess the word. If the user fails to guess after 3 times then it reveals the answer. I used a list on recommendation from a friend to read from the dictionary as it is quite large.
My question is, how can I read the list to choose a word for the guessing game?
{
static int letterLength, LettersLeft, wrongGuess;
public static void Main(string[] args)
{
string input = System.IO.File.ReadAllText("dictionary.txt");
string[] terms = input.Split();
List<string> list = new List<string>();
for (int num = 0; num < terms.Length; num++)
list.Add(terms[num]);
int wordToGuess = GetLengthOfWordToGuess();
List<string> fixedlist = new List<string>();
for (int num = 0; num < list.Count; num++)
{
string tempword = list[num];
if (tempword.Length == wordToGuess)
fixedlist.Add(tempword);
}
for (int num = 0; num < fixedlist.Count; num++)
Console.WriteLine(fixedlist[num]);
Console.WriteLine("Welcome to the guessing game");
letterLength = GetLengthOfWordToGuess();
Console.Clear();
//Not Working from here on.
string wordGuess = GetWordToGuess();
char[] maskedWord = GetHiddenLetters(wordGuess, '-');
LettersLeft = wordGuess.Length;
char userGuess;
wrongGuess = 3;
while (wrongGuess > 0 && LettersLeft > 0)
{
DispayCharacters(maskedWord);
Console.WriteLine("Enter a Letter");
userGuess = char.Parse(Console.ReadLine());
maskedWord = CheckGuess(userGuess, wordGuess, maskedWord);
}
Console.WriteLine("Well done! Thanks for Playing.");
Console.ReadLine();
}
static string GetWordToGuess()
{
Random word = new Random();
int wordNumber = word.Next(0, 9);
string[] words = { "" };
string selectWord = words[wordNumber];
return selectWord;
}
static char [] GetHiddenLetters(string word, char mask)
{
char[] hidden = new char[word.Length];
for (int i = 0; i < word.Length; i++)
{
hidden[i] = mask;
}
return hidden;
}
static void DispayCharacters(char [] characters)
{
foreach(char letter in characters)
{
Console.Write(letter);
Console.WriteLine();
}
}
static int GetLengthOfWordToGuess()
{
Console.WriteLine("Input length of word to guess");
int selectWord = int.Parse(Console.ReadLine());
return selectWord;
}
static char [] CheckGuess (char letterToCheck, string word, char [] characters)
{
bool wrong = true;
if(wrongGuess > 0)
{
for (int i = 0; i < word.Length; i++)
{
if (word[i] == letterToCheck)
{
characters[i] = word[i];
LettersLeft--;
wrong = false;
}
}
}
}
}
One major problem I see up front is that your GetWordToGuess function is not functional and probably throws an IndexOutOfRangeException.
The reason for that is that you are instantiating the words array as an array with a single empty string in it, but you are then referencing an index between 0 and 9, which will not exist in that array unless the random number generated is 0.
To solve this you should pass the fixedlist List you already created and use that instead of the words array. You should make sure to generate a random number between 0 and fixedlist.Count-1 so that you don't hit that same out of range exception. Therefore that function should look something like this:
static string GetWordToGuess(List<string> fixedlist)
{
Random word = new Random();
int wordNumber = word.Next(0, 9);
string[] words = { "" };
string selectWord = words[wordNumber];
return selectWord;
}
Also, as it stands right now, your included code doesn't compile because the CheckGuess function doesn't return a char[] as it says it should. I believe what you meant to do was have a return characters; line at the end (this was probably just a copy paste issue when you put your code in your question, but I thought I'd mention it just in case).
As a side note there are a number of small issues with your code like declaring things you don't use, but since they don't break your program I didn't want to go through and fix them.

Best way to split string into lines with maximum length, without breaking words

I want to break a string up into lines of a specified maximum length, without splitting any words, if possible (if there is a word that exceeds the maximum line length, then it will have to be split).
As always, I am acutely aware that strings are immutable and that one should preferably use the StringBuilder class. I have seen examples where the string is split into words and the lines are then built up using the StringBuilder class, but the code below seems "neater" to me.
I mentioned "best" in the description and not "most efficient" as I am also interested in the "eloquence" of the code. The strings will never be huge, generally splitting into 2 or three lines, and it won't be happening for thousands of lines.
Is the following code really bad?
private static IEnumerable<string> SplitToLines(string stringToSplit, int maximumLineLength)
{
stringToSplit = stringToSplit.Trim();
var lines = new List<string>();
while (stringToSplit.Length > 0)
{
if (stringToSplit.Length <= maximumLineLength)
{
lines.Add(stringToSplit);
break;
}
var indexOfLastSpaceInLine = stringToSplit.Substring(0, maximumLineLength).LastIndexOf(' ');
lines.Add(stringToSplit.Substring(0, indexOfLastSpaceInLine >= 0 ? indexOfLastSpaceInLine : maximumLineLength).Trim());
stringToSplit = stringToSplit.Substring(indexOfLastSpaceInLine >= 0 ? indexOfLastSpaceInLine + 1 : maximumLineLength);
}
return lines.ToArray();
}
Even when this post is 3 years old I wanted to give a better solution using Regex to accomplish the same:
If you want the string to be splitted and then use the text to be displayed you can use this:
public string SplitToLines(string stringToSplit, int maximumLineLength)
{
return Regex.Replace(stringToSplit, #"(.{1," + maximumLineLength +#"})(?:\s|$)", "$1\n");
}
If on the other hand you need a collection you can use this:
public MatchCollection SplitToLines(string stringToSplit, int maximumLineLength)
{
return Regex.Matches(stringToSplit, #"(.{1," + maximumLineLength +#"})(?:\s|$)");
}
NOTES
Remember to import regex (using System.Text.RegularExpressions;)
You can use string interpolation on the match:
$#"(.{{1,{maximumLineLength}}})(?:\s|$)"
The MatchCollection works almost like an Array
Matching example with explanation here
How about this as a solution:
IEnumerable<string> SplitToLines(string stringToSplit, int maximumLineLength)
{
var words = stringToSplit.Split(' ').Concat(new [] { "" });
return
words
.Skip(1)
.Aggregate(
words.Take(1).ToList(),
(a, w) =>
{
var last = a.Last();
while (last.Length > maximumLineLength)
{
a[a.Count() - 1] = last.Substring(0, maximumLineLength);
last = last.Substring(maximumLineLength);
a.Add(last);
}
var test = last + " " + w;
if (test.Length > maximumLineLength)
{
a.Add(w);
}
else
{
a[a.Count() - 1] = test;
}
return a;
});
}
I reworked this as prefer this:
IEnumerable<string> SplitToLines(string stringToSplit, int maximumLineLength)
{
var words = stringToSplit.Split(' ');
var line = words.First();
foreach (var word in words.Skip(1))
{
var test = $"{line} {word}";
if (test.Length > maximumLineLength)
{
yield return line;
line = word;
}
else
{
line = test;
}
}
yield return line;
}
I don't think your solution is too bad. I do, however, think you should break up your ternary into an if else because you are testing the same condition twice. Your code might also have a bug. Based on your description, it seems you want lines <= maxLineLength, but your code counts the space after the last word and uses it in the <= comparison resulting in effectively < behavior for the trimmed string.
Here is my solution.
private static IEnumerable<string> SplitToLines(string stringToSplit, int maxLineLength)
{
string[] words = stringToSplit.Split(' ');
StringBuilder line = new StringBuilder();
foreach (string word in words)
{
if (word.Length + line.Length <= maxLineLength)
{
line.Append(word + " ");
}
else
{
if (line.Length > 0)
{
yield return line.ToString().Trim();
line.Clear();
}
string overflow = word;
while (overflow.Length > maxLineLength)
{
yield return overflow.Substring(0, maxLineLength);
overflow = overflow.Substring(maxLineLength);
}
line.Append(overflow + " ");
}
}
yield return line.ToString().Trim();
}
It is a bit longer than your solution, but it should be more straightforward. It also uses a StringBuilder so it is much faster for large strings. I performed a benchmarking test for 20,000 words ranging from 1 to 11 characters each split into lines of 10 character width. My method completed in 14ms compared to 1373ms for your method.
Try this (untested)
private static IEnumerable<string> SplitToLines(string value, int maximumLineLength)
{
var words = value.Split(' ');
var line = new StringBuilder();
foreach (var word in words)
{
if ((line.Length + word.Length) >= maximumLineLength)
{
yield return line.ToString();
line = new StringBuilder();
}
line.AppendFormat("{0}{1}", (line.Length>0) ? " " : "", word);
}
yield return line.ToString();
}
~6x faster than the accepted answer
More than 1.5x faster than the Regex version in Release Mode (dependent on line length)
Optionally keep the space at the end of the line or not (the regex version always keeps it)
static IEnumerable<string> SplitToLines(string stringToSplit, int maximumLineLength, bool removeSpace = true)
{
int start = 0;
int end = 0;
for (int i = 0; i < stringToSplit.Length; i++)
{
char c = stringToSplit[i];
if (c == ' ' || c == '\n')
{
if (i - start > maximumLineLength)
{
string substring = stringToSplit.Substring(start, end - start); ;
start = removeSpace ? end + 1 : end; // + 1 to remove the space on the next line
yield return substring;
}
else
end = i;
}
}
yield return stringToSplit.Substring(start); // remember last line
}
Here is the example code used to test speeds (again, run on your own machine and test in Release mode to get accurate timings)
https://dotnetfiddle.net/h5I1GC
Timings on my machine in release mode .Net 4.8
Accepted Answer: 667ms
Regex: 368ms
My Version: 117ms
My requirement was to have a line break at the last space before the 30 char limit.
So here is how i did it. Hope this helps anyone looking.
private string LineBreakLongString(string input)
{
var outputString = string.Empty;
var found = false;
int pos = 0;
int prev = 0;
while (!found)
{
var p = input.IndexOf(' ', pos);
{
if (pos <= 30)
{
pos++;
if (p < 30) { prev = p; }
}
else
{
found = true;
}
}
outputString = input.Substring(0, prev) + System.Environment.NewLine + input.Substring(prev, input.Length - prev).Trim();
}
return outputString;
}
An approach using recursive method and ReadOnlySpan (Tested)
public static void SplitToLines(ReadOnlySpan<char> stringToSplit, int index, ref List<string> values)
{
if (stringToSplit.IsEmpty || index < 1) return;
var nextIndex = stringToSplit.IndexOf(' ');
var slice = stringToSplit.Slice(0, nextIndex < 0 ? stringToSplit.Length : nextIndex);
if (slice.Length <= index)
{
values.Add(slice.ToString());
nextIndex++;
}
else
{
values.Add(slice.Slice(0, index).ToString());
nextIndex = index;
}
if (stringToSplit.Length <= index) return;
SplitToLines(stringToSplit.Slice(nextIndex), index, ref values);
}

How to cast an 'int' to a 'char' in C#?

I have a string variable which has a mixture of numbers and letters. I want to create a new string that only has int values of the previous string variable. So I found two ways to cast int to char. However, they do not work. Here's what I've tried
string onlyNumberString = "";
foreach (char onlyNum in puzzleData)
{
for (int i = 1; i < 10; i++)
{
if (onlyNum == (char)i)
{
onlyNumberString += onlyNum;
}
}
}
and
string onlyNumberString = "";
foreach (char onlyNum in puzzleData)
{
for (int i = 1; i < 10; i++)
{
if (onlyNum == Convert.ToChar(i))
{
onlyNumberString += onlyNum;
}
}
}
Use Char.IsDigit instead, far simpler.
StringBuilder onlyNumber = new StringBuilder();
foreach (char onlyNum in puzzleData)
{
if (Char.IsDigit(onlyNum))
{
onlyNumber.Append(onlyNum);
}
}
int iNum = 2;
char cChar = iNum.ToString()[0];
Will work for x when 0 <= x <= 9.
You can just cast an int to a char it directly:
var myChar = (char)20;
But to do what you want I suggest using a regular expression:
var onlyNumerals = Regex.Replace(myString, #"[^0-9]", "");
The above will replace any character that is not 0-9 with an empty space.
An alternative, using LINQ and char.IsDigit:
var onlyNumeral = new string(myString.Where(c => Char.IsDigit(c)).ToArray());
You can do it as:
string justNumbers = new String(text.Where(Char.IsDigit).ToArray());
A few ways:
(char)int
Or
int.Parse(char.ToString())
Or
Convert.ToChar(int);

Find all pattern indexes in string in C#

How can I find all indexes of a pattern in a string using c#?
For example I want to find all ## pattern indexes in a string like this 45##78$$#56$$JK01UU
string pattern = "##";
string sentence = "45##78$$#56$$J##K01UU";
IList<int> indeces = new List<int>();
foreach (Match match in Regex.Matches(sentence, pattern))
{
indeces.Add(match.Index);
}
indeces will have 2, 14
Edited the code to make it a cleaner function.
public IEnumerable<int> FindAllIndexes(string str, string pattern)
{
int prevIndex = -pattern.Length; // so we start at index 0
int index;
while((index = str.IndexOf(pattern, prevIndex + pattern.Length)) != -1)
{
prevIndex = index;
yield return index;
}
}
string str = "45##78$$#56$$JK01UU";
string pattern = "##";
var indexes = FindAllIndexes(str, pattern);
You can get all the indices of a pattern in a string by using a regex search like this.
string input = "45##78$$#56$$JK01UU", pattern = Regex.Escape("##");
Regex rx = new Regex(pattern);
var indices = new List<int>();
var matches = rx.Matches(s);
for (int i=0 ; i<matches.Length ; i++)
{
indices.Add(matches[i].Index);
}
Another one that tries to be efficient:
public IEnumerable<int> FindPatternIndexes(string input, string search)
{
var sb = new StringBuilder(input);
for (var i = 0; search.Length <= sb.Length; i++)
{
if (sb.ToString().StartsWith(search)) yield return i;
sb.Remove(0,1);
}
}
Tested. Worked. But somewhat dumb.
string foo = "45##78$$#56$$JK01UU";
char[] fooChar = foo.ToCharArray();
int i = 0;
bool register = false;
foreach (char fc in fooChar)
{
if (fc == '#' && register == true)
{
MessageBox.Show("Index: " + (i-1));
}
else if (fc == '#')
{
register = true;
}
else
{
register = false;
}
i++;
}

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