CODEWITHSUNDEEP
c#stringsequence
user1765216
user1765216

Reputation: 111

c# number sequence

I have made this code to get from 2a3b to aabbb. This also has to apply when no numbers are given. Like aa2b => aabb. The program is fully working but my problem is, it takes in alot of space. I think it is my split but my array will be like this if the input is 2a2b:

2 NULL NULL a 2 NULL NULL b

Does someone know what i'm doing wrong? Is it my split?

static void Main(string[] args)
        {
            string test = "";
            int intNumber = 1;

            string value = "2a2b";
            string[] array = new string[20];
            int count = 1;

            array = Regex.Split(value, "(\\d{0,2})");

            while (count < array.Length)
            {
                int num;
                if (array[count] != "")
                {
                    bool isNumeric = int.TryParse(array[count], out num);
                    if (!isNumeric)
                    {

                        test = test + string.fill(array[count], intNumber);
                        test = test + array[count];

                        Console.WriteLine(test);

                        intNumber = 1;
                    }
                    else
                    {
                        intNumber = num;

                    }  
                }
                count++;
            }
            Console.WriteLine("woord:" + test);


            Console.ReadLine();

Upvotes: 0

Views: 1769

Answers (4)

Novak
Novak

Reputation: 2768

I generally try to avoid Regex, unless there is a complex pattern I need to verify.

Here is my solution to your problem:

string k = Console.ReadLine();

string t = "";
int count = 0, next;

for (int i = 0; i < k.Length; i++)
{
    while (int.TryParse(k[i].ToString(), out next)) // Find the count of the next letter
    {
        count = count * 10 + next; // If count had a 2, and the next character is 3 (means we need to calculate 23), simply multiply the previous count by 10, and add the new digit
        i++; // Move to the next character
    }

    t += new String(k[i], count > 0 ? count : 1); // Add the new sequence of letters to our string
    count = 0; // Clear the current count
}

Console.WriteLine(t);

You can optimize the above, by using the StringBuilder class, but I think it's enough to understand the general solution first, rather than trying to find optimizations.

Upvotes: 0

Charles380
Charles380

Reputation: 1279

Quick test program works like a charm without using a regex.

const string value = "aa2b";
var result = "";

for (var i = 0; i < value.Length; i++)
{
     int num;
     if (Int32.TryParse(value.Substring(i, 1), out num))
     {
         for (var j = 0; j < num; j++)
         {
            result += value.Substring(i + 1, 1);
         }
            i++;
     }
     else
     {
         result += value.Substring(i, 1);
     }
}

textBox1.AppendText("woord:" + result);

Upvotes: 0

I4V
I4V

Reputation: 35353

How about using a simple Regex.Replace?

string input = "2a3bcccc";
string output = Regex.Replace(
         input, 
         @"(\d+)(\w)", 
         m => new String(m.Groups[2].Value[0],int.Parse(m.Groups[1].Value)));

result : aabbbcccc

Upvotes: 1

RMalke
RMalke

Reputation: 4094

A simpler way to resolve your problem is to get rid of regex, the array creation would be like:

 char[] array = value.ToArray();

The code, with the minor corrections due to the array and some improvements being a char array (intead of a string array):

static void Main(string[] args)
{
    string test = "";
    int intNumber = 1;

    string value = "2a2b";

    foreach (char c in value.ToArray())
    {
        int num;
        bool isNumeric = int.TryParse(c.ToString(), out num);

        if (!isNumeric)
        {
            test = test + new string(c, intNumber);

            Console.WriteLine(test);

            intNumber = 1;
        }
        else
        {
            intNumber = num;
        }
    }

    Console.WriteLine("woord:" + test);
    Console.ReadLine();
}

Upvotes: 0

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