Sorting String Using Radix Sort

[Lost User]

gamer1127 wrote:

CharAt() method? Is that Java?

Yes. In C#, you can index a string as if it were an array. The elements are of type char, and of course read-only.

[gamer1127]

This is the source code that I got. It's a msd Radix sort:

public static void msd(String[] a)
{
msd(a, 0, a.Length, 0);
}

    private static void msd(String\[\] a, int l, int r, int d)
    {
        int N = a.Length;

        if (r <== l + 1) return;
        int\[\] count = new int\[256\];
        for (int i = 0; i < N; i++)
            count\[a\[i\].charAt(d) + 1\]++;
        for (int k = 1; k < 256; k++)
            count\[k\] += count\[k-1\];
        for (int i = 0; i < N; i++)
            temp\[count\[a\[i\].charAt(d)\]++\] = a\[i\];
        for (int i = 0; i < N; i++)
            a\[i\] = temp\[i\];
        for (int i = 1; i < 255; i++)
            msd(a, l + count\[i\], l + count\[i+1\], d+1);
    }

How will I revise this so I can use it in c#?

[Lost User]

count[a[i].charAt(d) + 1] -> count[a[i][d] + 1]

[gamer1127]

I'm still having a problem with my string sorting. I always get the IndexOutOfRange exception during runtime. How will I solve that?

public static void SortByLastName(ref string[] arrayOfLastNames, ref string[] arrayOfFirstNames, ref string[] arrayOfPlateNum, ref string[] arrayOfType, ref string[] arrayOfYear)
{
Console.Clear();

        int vehicleCountInt = 0;
       
        Console.WriteLine("SHOW DATABASE: SORTING BY LAST NAME\\n");

        using (StreamReader countVehicle = new StreamReader("vehiclecount.txt"))
        {
            vehicleCountInt = Int32.Parse(countVehicle.ReadLine());
        }

        using (StreamReader outputLastNames = new StreamReader("lastnames.txt"))
        {
            int\[\] b = new int\[vehicleCountInt + 1\]; ;

            for (int i = 0; i < vehicleCountInt; i++)
            {
                arrayOfLastNames\[i\] = outputLastNames.ReadLine();

                Console.WriteLine();
            }

        }

        int N = arrayOfLastNames.Length;
        int W = arrayOfLastNames\[0\].Length;
        string\[\] temp = new string\[vehicleCountInt\];

        for (int d = W - 1; d >= 0; d--)
        {
            int\[\] count = new int\[vehicleCountInt\];
            for (int i = 0; i < N; i++)
            {
                count\[arrayOfLastNames\[i\]\[d\] + 1\]++;//the part that causes the run-time error
            }
            for (int k = 1; k < 256; k++)
            {
                count\[k\] += count\[k - 1\];
            }
            for (int i = 0; i < N; i++)
            {
                temp\[count\[arrayOfLastNames\[i\]\[d\]\]++\] = arrayOfLastNames\[i\];
            }
            for (int i = 0; i < N; i++)
            {
                arrayOfLastNames\[i\] = temp\[i\];

                Console.WriteLine("{0}", arrayOfLastNames\[i\]);
            }
        }
    }

[Lost User]

You don't need ref for those arrays, you're not assigning to them But wait, how can you be sure that those arrays are long enough? tip: always tell where you get the exception. I suspect it happens here: arrayOfLastNames[i] = outputLastNames.ReadLine(); Since there is no guarantee that arrayOfLastNames is long enough (its length is unknown)

[gamer1127]

Ok..Is there a way on how to solve that problem? I'm thinking of declaring an array that is large enough for me to store those names.

[Lost User]

I hope you aren't asking for a way to declare an array of a given size.. int[] b = new int[vehicleCountInt + 1]; is one such declaration, but probably 1 too big (why are you adding one?) If you are asking how to assign to an array which is a function parameter, well, ref is used for exactly that purpose, but out may be sufficient. But this "problem" is as trivial as the first.

[gamer1127]

Well I'm referring to how will I solve the problem about the uncertainty of the array's size. I've declared 5 text files with 30 data inside. Now what my groupmate did was create a text file and put there the total number of data inside the text files, and that's the vehicleCount. Now what I'm thinking is declare an array that has a definite size (say 50) which will hold the data inside the text file(the 30 predefined data and the user's additional inputs). Will this solve the problem about the IndexOutOfRange exception?

[ghelhei]

string strRaw = "Thisisastring"; char[] astrSorted = strRaw.ToCharArray().ToArray(); Array.Sort(astrSorted); string strSorted = String.Empty; foreach (char strChar in astrSorted) { strSorted += strChar; } eto try mo dn tong code nato

[ghelhei]

[Message Deleted]

[Lost User]

Declaring an array to be intentionally too big is not really nice You could make it a List or read the file all at once and then split on newlines

[gamer1127]

Your right...It didn't solve the problem..I'm sticking to the original code that we created (having a text file that acts like a counter).