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Custom pattern matching in C#

Currently I am making a AI based on text.
I have a database with a pattern for each answer
A pattern looks like [Who is the] Winner of the World Cup 2018
[] = Optional words
<> = Needed words
When I enter the sentence Who is the Winner of the World Cup 2018 my method should return the indentifier of the answer.
My database has 2 rows called "AnswerIndentifier" and "Pattern"

I did it myself and programmed this algoryhm:
private static bool MatchesPattern(string text, string pattern)
{
List<string> patternTokens = new List<string>();
string tok = "";
pattern = pattern.ToLower() + "[";
int state = 0;
for(int i = 0; i < pattern.ToCharArray().Length; i++)
{
char token = pattern[i];
if(token == '[')
{
if(tok != "")
{
patternTokens.Add("NEC" + char.MaxValue + tok);
tok = "";
}
state = 1;
continue;
}
if(token == ']' && state == 1)
{
i++;
state = 0;
patternTokens.Add("OPT" + char.MaxValue + tok);
tok = "";
continue;
}
if(token == ' ' && i + 1 < text.ToCharArray().Length && text[i + 1] == '[')
continue;
tok += token;
}
string[] patternTokensCopy = new string[patternTokens.Count];
for(int i = 0; i < patternTokens.Count; i++)
patternTokensCopy[i] = patternTokens[i];
int max = (int) Math.Pow(2, patternTokens.Where(x => x.StartsWith("OPT")).ToList().Count);
for(int i = 0; i < max; i++)
{
string binary = Convert.ToString(i, 2).PadLeft(patternTokensCopy.Where(x => x.StartsWith("OPT")).ToList().Count, '0');
for(int x = 0; x < patternTokensCopy.Where(t => t.StartsWith("OPT")).ToList().Count; x++)
if(binary[x] == '0')
{
List<string> optionalTokens = new List<string>();
foreach(string curpattern in patternTokensCopy)
if(curpattern.StartsWith("OPT"))
optionalTokens.Add(curpattern);
patternTokens.Remove(optionalTokens[x]);
}
string patternAsSentence = "";
foreach(string patternToken in patternTokens)
patternAsSentence += patternToken.Split(char.MaxValue)[1] + " ";
while(patternAsSentence[patternAsSentence.Length - 1] == ' ')
patternAsSentence = patternAsSentence.Substring(0, patternAsSentence.Length - 1);
patternAsSentence = patternAsSentence.Replace("\r", "").Replace(" ", " ");
int similarity = StringSimilarity.GetStringSimilarity(patternAsSentence, text);
if(text.Length < 6)
{
if(text == patternAsSentence)
return true;
}
else
{
if(similarity <= 6)
return true;
}
patternTokens = new List<string>();
patternTokensCopy.ToList().ForEach(x => patternTokens.Add(x));
}
return false;
}
The only changes are that the needed text must not marked with <> and the similarity check(see C# - Compare String Similarity)

C# Hangman IndexOf Loop

I am a beginner in C# and i am trying to make a "hangman" game. I got stuck at the process when the player guess a letter.
If the word for example is DATA, the application only gets the first A in DATA.
I understand that i have to loop the word to get all the A´s but i am having touble with making it work!
here is my code for the method myGuess:
public void myGuess(String letter)
{
int plats = 0;
string wordToGuess = label4.Text;
plats = wordToGuess.IndexOf(letter);
string wordToShow = label5.Text;
//ersätt "_" med bokstaven på alla positioner bokstaven dyker upp
wordToShow = wordToShow.Substring(0, wordToGuess.IndexOf(letter)) + letter +
wordToShow.Substring(plats + 1, wordToShow.Length - (plats + 1));
label5.Text = wordToShow;
}
I have been trying to google it but because i am a beginner i don't understand the
suggestions people give. Hopefully it is a way to loop for more than one letter with IndexOf?

IndexOf returns the index of the first instance of the character in the string. You could manipulate your string using substring, but you'd be making it more complicated than you need to need. Instead, you can just loop through each of the characters in the String with a for loop:
for (int i = 0; i < wordToGuess.Length; i++ )
{
if (WordToGuess[i] == letter)
{
//Update the correctly guessed letters, (using value of i to determine which letter to make visible.)
}
}
label5.Text = wordToShow;

You can use this:
label4(wordToGuess): DATA
label5(wordToShow): ****
When you call myGuess('A')
label4(wordToGuess): DATA
label5(wordToShow): *A*A
When you call myGuess('T')
label4(wordToGuess): DATA
label5(wordToShow): *ATA
...
public void myGuess(char letter)
{
string wordToGuess = label4.Text;
string wordToShow = label5.Text;
if (wordToShow.Length == 0)
{
for (int i = 0; i < wordToGuess.Length; i++)
wordToShow += "*";
}
for (int i = 0; i < wordToGuess.Length; i++)
{
if (wordToGuess[i] == letter || wordToGuess[i] == wordToShow[i])
wordToShow = wordToShow.Remove(i,1).Insert(i, Char.ToString(letter));
}
label5.Text = wordToShow;
}

Here's a long solution that's probably overly generic.
List<int> findIndexes(string myStr, char letter)
{
var foundIndexes = new List<int>();
for (int i = 0; i < myStr.Length; i++)
{
if (myStr[i] == letter)
foundIndexes.Add(i);
}
return foundIndexes;
}
string ReplaceIndex(string s, int index, char letter){
return s.Substring(0, index )
+ letter
+ s.Substring(index + 1, s.Length - (index + 1));
}
void Main()
{
string s= "data";
string wordToShow = "____";
var letter = 'a';
var indexes = findIndexes(s, letter);
foreach (var index in indexes)
{
wordToShow = ReplaceIndex(wordToShow, index, letter);
}
Console.WriteLine (wordToShow);
}

A simple for loop should handle it.
for (int i = 0; i < wordToGuess.Length; i++)
{
if (wordToGuess[i].ToString().Equals(letter.ToString(), System.StringComparison.InvariantCultureIgnoreCase))
{
wordToShow = string.Format("{0}{1}{2}", wordToShow.Substring(0, i), letter, wordToShow.Substring(i, wordToShow.Length - (i + 1)));
}
}
Here's a fiddle: http://dotnetfiddle.net/UATeVJ

Changing commas within quotes

I am trying to read the data in a text file which is separated by commas. My problem, is that one of my data pieces has a comma within it. An example of what the text file looks like is:
a, b, "c, d", e, f.
I want to be able to take the comma between c and d and change it to a semicolon so that I can still use the string.Split() method.
using (StreamReader reader = new StreamReader("file.txt"))
{
string line;
while ((line = reader.ReadLine ()) != null) {
bool firstQuote = false;
for (int i = 0; i < line.Length; i++)
{
if (line [i] == '"' )
{
firstQuote = true;
}
else if (firstQuote == true)
{
if (line [i] == '"')
{
break;
}
if ((line [i] == ','))
{
line = line.Substring (0, i) + ";" + line.Substring (i + 1, (line.Length - 1) - i);
}
}
}
Console.WriteLine (line);
}
I am having a problem. Instead of producing
a, b, "c; d", e, f
it is producing
a, b, "c; d"; e; f
It is replacing all of the following commas with semicolons instead of just the comma in the quotes. Can anybody help me fix my existing code?

Basically if you find a closing " you recognize it as it was an opening quote.
Change the line:
firstQuote = true;
to
firstQuote = !firstQuote;
and it should work.

You need to reset firstquote to false after you hit the second quote.
else if (firstQuote == true) {
if (line [i] == '"') {
firstquote = false;
break;
}

Here is a simple application to get the required result
static void Main(string[] args)
{
String str = "a,b,\"c,d\",e,f,\"g,h\",i,j,k,l,\"m,n,o\"";
int firstQuoteIndex = 0;
int secodQuoteIndex = 0;
Console.WriteLine(str);
bool iteration = false;
//String manipulation
//if count is even then count/2 is the number of pairs of double quotes we are having
//so we have to traverse count/2 times.
int count = str.Count(s => s.Equals('"'));
if (count >= 2)
{
firstQuoteIndex = str.IndexOf("\"");
for (int i = 0; i < count / 2; i++)
{
if (iteration)
{
firstQuoteIndex = str.IndexOf("\"", firstQuoteIndex + 1);
}
secodQuoteIndex = str.IndexOf("\"", firstQuoteIndex + 1);
string temp = str.Substring(firstQuoteIndex + 1, secodQuoteIndex - (firstQuoteIndex + 1));
firstQuoteIndex = secodQuoteIndex + 1;
if (count / 2 > 1)
iteration = true;
string temp2= temp.Replace(',', ';');
str = str.Replace(temp, temp2);
Console.WriteLine(temp);
}
}
Console.WriteLine(str);
Console.ReadLine();
}
Please feel free to ask in case of doubt

string line = "a,b,mc,dm,e,f,mk,lm,g,h";
string result =replacestr(line, 'm', ',', ';');
public string replacestr(string line,char seperator,char oldchr,char newchr)
{
int cnt = 0;
StringBuilder b = new StringBuilder();
foreach (char chr in line)
{
if (cnt == 1 && chr == seperator)
{
b[b.ToString().LastIndexOf(oldchr)] = newchr;
b.Append(chr);
cnt = 0;
}
else
{
if (chr == seperator)
cnt = 1;
b.Append(chr);
}
}
return b.ToString();
}

Unable to use an index on the selected item of a ListBox

I have this:
string curr = "";
if (emails.SelectedItem != null)
{
for (int i = 0; i <= 19; i++)
{
curr = (emails.SelectedItem.ToString()[i] + "." +
emails.SelectedItem.ToString()[i + 1]);
clone.Items.Add(curr);
}
}
However, whenever I run it, it gives me the "index was out of bounds of the array" error.
Why? What's the fix?
Also, how do I make it add the rest of the string (not just i + 1) to clone?
EXPLANATION OF CODE:
I'm trying to insert a period (.) after one letter of the word, then add it to clone. After that, I want to add a period after the SECOND letter, add to clone, period after third letter, add, etc...
However, I don't want to have it be t.h.i.s.i.s.t.h.e.n.a.m.e, I want it to just have one period at a time.
It should look like:
a.ntimatter
an.timatter
ant.imatter
anti.matter
etc...

if (emails.SelectedItem != null)
{
var item = emails.SelectedItem.ToString();
for (int i = 1; i < item.Length; i++)
{
clone.Items.Add(item.Insert(i, "."));
}
}

Try this
if (emails.SelectedItem != null) {
string text = emails.SelectedItem.ToString();
for (int i = 1; i < text.Length; i++) {
string textWithPeriod = text.Substring(0, i) + "." + text.Substring(i);
clone.Items.Add(textWithPeriod);
}
}

Count occurences in byte list/array using another byte list/array

I am trying to get a count of all the times a byte sequences occurs in another byte sequences. It cannot however re-use a bytes if it already counted them. For example given the string
k.k.k.k.k.k. let's assume the byte sequence was k.k it would then find only 3 occurrences rather than 5 because they would be broke down like: [k.k].[k.k].[k.k]. and not like [k.[k].[k].[k].[k].k] where they over lap and essentially just shift 2 to the right.
Ideally the idea is to get an idea how a compression dictionary or run time encoding might look. so the goal would be to get
k.k.k.k.k.k. down to just 2 parts, as (k.k.k.) is the biggest and best symbol you can have.
Here is source so far:
using System;
using System.Collections.Generic;
using System.Collections;
using System.Linq;
using System.Text;
using System.IO;
static class Compression
{
static int Main(string[] args)
{
List<byte> bytes = File.ReadAllBytes("ok.txt").ToList();
List<List<int>> list = new List<List<int>>();
// Starting Numbers of bytes - This can be changed manually.
int StartingNumBytes = bytes.Count;
for (int i = StartingNumBytes; i > 0; i--)
{
Console.WriteLine("i: " + i);
for (int ii = 0; ii < bytes.Count - i; ii++)
{
Console.WriteLine("ii: " + i);
// New pattern comes with refresh data.
List<byte> pattern = new List<byte>();
for (int iii = 0; iii < i; iii++)
{
pattern.Add(bytes[ii + iii]);
}
DisplayBinary(bytes, "red");
DisplayBinary(pattern, "green");
int matches = 0;
// foreach (var position in bytes.ToArray().Locate(pattern.ToArray()))
for (int position = 0; position < bytes.Count; position++) {
if (pattern.Count > (bytes.Count - position))
{
continue;
}
for (int iiii = 0; iiii < pattern.Count; iiii++)
{
if (bytes[position + iiii] != pattern[iiii])
{
//Have to use goto because C# doesn't support continue <level>
goto outer;
}
}
// If it made it this far, it has found a match.
matches++;
Console.WriteLine("Matches: " + matches + " Orig Count: " + bytes.Count + " POS: " + position);
if (matches > 1)
{
int numBytesToRemove = pattern.Count;
for (int ra = 0; ra < numBytesToRemove; ra++)
{
// Remove it at the position it was found at, once it
// deletes the first one, the list will shift left and you'll need to be here again.
bytes.RemoveAt(position);
}
DisplayBinary(bytes, "red");
Console.WriteLine(pattern.Count + " Bytes removed.");
// Since you deleted some bytes, set the position less because you will need to redo the pos.
position = position - 1;
}
outer:
continue;
}
List<int> sublist = new List<int>();
sublist.Add(matches);
sublist.Add(pattern.Count);
// Some sort of calculation to determine how good the symbol was
sublist.Add(bytes.Count-((matches * pattern.Count)-matches));
list.Add(sublist);
}
}
Display(list);
Console.Read();
return 0;
}
static void DisplayBinary(List<byte> bytes, string color="white")
{
switch(color){
case "green":
Console.ForegroundColor = ConsoleColor.Green;
break;
case "red":
Console.ForegroundColor = ConsoleColor.Red;
break;
default:
break;
}
for (int i=0; i<bytes.Count; i++)
{
if (i % 8 ==0)
Console.WriteLine();
Console.Write(GetIntBinaryString(bytes[i]) + " ");
}
Console.WriteLine();
Console.ResetColor();
}
static string GetIntBinaryString(int n)
{
char[] b = new char[8];
int pos = 7;
int i = 0;
while (i < 8)
{
if ((n & (1 << i)) != 0)
{
b[pos] = '1';
}
else
{
b[pos] = '0';
}
pos--;
i++;
}
//return new string(b).TrimStart('0');
return new string(b);
}
static void Display(List<List<int>> list)
{
//
// Display everything in the List.
//
Console.WriteLine("Elements:");
foreach (var sublist in list)
{
foreach (var value in sublist)
{
Console.Write("{0,4}", value);
}
Console.WriteLine();
}
//
// Display total count.
//
int count = 0;
foreach (var sublist in list)
{
count += sublist.Count;
}
Console.WriteLine("Count:");
Console.WriteLine(count);
}
static public int SearchBytePattern(byte[] pattern, byte[] bytes)
{
int matches = 0;
// precomputing this shaves some seconds from the loop execution
int maxloop = bytes.Length - pattern.Length;
for (int i = 0; i < maxloop; i++)
{
if (pattern[0] == bytes[i])
{
bool ismatch = true;
for (int j = 1; j < pattern.Length; j++)
{
if (bytes[i + j] != pattern[j])
{
ismatch = false;
break;
}
}
if (ismatch)
{
matches++;
i += pattern.Length - 1;
}
}
}
return matches;
}
}
Refer to the post to get the non binary of the file should be, here is the binary data:
011010110010111001101011001011100110101100101110011010110010111001101011001011100110101100101110 I am hope to have it smaller than how it started.

private static int CountOccurences(byte[] target, byte[] pattern)
{
var targetString = BitConverter.ToString(target);
var patternString = BitConverter.ToString(pattern);
return new Regex(patternString).Matches(targetString).Count;
}

With this solution you'd have access to the individual indexes that matched (while enumerating) or you could call Count() on the result to see how many matches there were:
public static IEnumerable<int> Find<T>(T[] pattern, T[] sequence, bool overlap)
{
int i = 0;
while (i < sequence.Length - pattern.Length + 1)
{
if (pattern.SequenceEqual(sequence.Skip(i).Take(pattern.Length)))
{
yield return i;
i += overlap ? 1 : pattern.Length;
}
else
{
i++;
}
}
}
Call it with overlap: false to solve your problem or overlap: true to see the overlapped matches (if you're interested.)
I have a couple of other methods with slightly different API (along with better performance) here, including one that work directly on streams of bytes.

quick and dirty with no regex. although i'm not sure if it answers the intent of the question, it should be relatively fast. i think i am going to run some timing tests against regex to see for sure the relative speeds:
private int CountOccurrences(string TestString, string TestPattern)
{
int PatternCount = 0;
int SearchIndex = 0;
if (TestPattern.Length == 0)
throw new ApplicationException("CountOccurrences: Unable to process because TestPattern has zero length.");
if (TestString.Length == 0)
return 0;
do
{
SearchIndex = TestString.IndexOf(TestPattern, SearchIndex);
if (SearchIndex >= 0)
{
++PatternCount;
SearchIndex += TestPattern.Length;
}
}
while ((SearchIndex >= 0) && (SearchIndex < TestString.Length));
return PatternCount;
}
private void btnTest_Click(object sender, EventArgs e)
{
string TestString1 = "k.k.k.k.k.k.k.k.k.k.k.k";
string TestPattern1 = "k.k";
System.Console.WriteLine(CountOccurrences(TestString1, TestPattern1).ToString()); // outputs 6
System.Console.WriteLine(CountOccurrences(TestString1 + ".k", TestPattern1).ToString()); // still 6
System.Console.WriteLine(CountOccurrences(TestString1, TestPattern1 + ".").ToString()); // only 5
}