hi everyone

                       can you please help me

here is my question:

                             i want to get 10 names as well as 10 ratings from user...i want to sort an array using ratings as well as i want to sort it in an decending order...

example:

my output will be

enter the name x

enter the name x

enter the name x

enter the name x

enter the name x

enter the name x

enter the name x

enter the name x

enter the name x

enter the name x

 

enter the ratings 5 star

enter the ratings 2 star

enter the ratings 5 star

enter the ratings 3 star

enter the ratings 6 star

enter the ratings 5 star

enter the ratings 5 star

enter the ratings 5 star

enter the ratings 4 star

enter the ratings 5 star

 

ascending order

x  2star 

x  3star 

x 4 star

x 5 star

 x 5 star

x 5 star 

x  5 star

x 5star

x 5star

 

decending order

x 5 star

 x 5 star

x 5 star 

x  5 star

x 5star

x 5star

x 4 star

x  3star

x  2star

 

 Thanks

 

 

 

  

We will help you but you should also remember to mark the posts that answered your question as Answer.

 yes sure

thanks 

Did you try anything?

 yes

 but i am not sure about this..because now only i am studying c#

using System;

class TDMArray
{
    public static void Main()
    {
        string[,] mymatrix;
        mymatrix = new string[10, 10];
 

        for (int i=0; i<=10; i++)
        {
            for (int j=0; j<=10; j++)
            {
                Console.Write("Please enter the Names");
                mymatrix[i,j] = Console.ReadLine();


            }
            //Console.Write("please enter the ratings");(this is wrong)
            //mymatrix[j , i ] = Console.ReadLine();(this is wrong)





        }
        Array.Sort(mymatrix);
        foreach (String person in mymatrix)
        {
            // i dont know how to write
        }
    }
}
         
       

please help me... 

This uses a heap sort. It might be take some time for you to figure out how heap sort works but its worth it. If you can, read about it and then see how it is implemented here.

     static void Main(string[] args)
        {
            string[,] name = new string[10,2];
            for (int i = 0; i <= 9; i++)
            {
                Console.Write("Please enter a name ");
                name[i,0] = Console.ReadLine();
                Console.Write("Please enter a rank ");
                name[i,1] = Console.ReadLine();
            }

            Console.WriteLine(name.Length.ToString());
            sortArray(name, name.Length/2 - 1);

            for (int i = 0; i <= 9; i++)
            {
                Console.WriteLine(name[i,0] + " " + name[i, 1]);
            }
   
               Console.Read();
        }

        public static void sortArray(string[,] a, int x)
        {
            int i;
            string temp;
            string strTemp;

            for (i = (x / 2) - 1; i >= 0; i--)
            {
                siftDown(a, i, x);
            }

            for (i = x - 1; i >= 1; i--)
            {
                //swapping values at indices 0 & 1
                temp = a[0, 1];
                a[0, 1] = a[i, 1];
                a[i, 1] = temp;

                strTemp = a[0, 0];
                a[0, 0] = a[i, 0];
                a[i, 0] = strTemp;

                siftDown(a, 0, i - 1);
            }
        }

        /// <summary>
        /// This method is used my sortArray() 
        /// </summary>
        /// <param name="a"></param>
        /// <param name="root"></param>
        /// <param name="bottom"></param>
        public static void siftDown(string[,] a, int root, int bottom)
        {
            bool done = false;
            int maxChild;
            string temp;
            string strTemp;

            while ((root * 2 <= bottom) && (!done))
            {
                if (root * 2 == bottom)
                    maxChild = root * 2;
                else if (Convert.ToDouble(a[root * 2, 1]) < Convert.ToDouble(a[root * 2 + 1, 1]))
                    maxChild = root * 2;
                else
                    maxChild = root * 2 + 1;


                if (Convert.ToDouble(a[root, 1]) > Convert.ToDouble(a[maxChild, 1]))
                {
                    //swapping values at indices 0 & 1
                    temp = a[root, 1];
                    a[root, 1] = a[maxChild, 1];
                    a[maxChild, 1] = temp;

                    strTemp = a[root, 0];
                    a[root, 0] = a[maxChild, 0];
                    a[maxChild, 0] = strTemp;

                    root = maxChild;
                }
                else
                {
                    done = true;
                }
            }
        }

   

 

 thank you so much

is there any other  simple way to solve this problem 

 thanks alot

i more doubt..can you please tell me ..how to sort an twodimensional array in very simple manner

for example

using System;

class TDMArray
{
    public static void Main()
    {
        string[,] mymatrix;
        mymatrix = new string[10, 10];


        for (int i = 0; i <= 9; i++)
        {


            Console.Write("Please enter the Names");
            mymatrix[i, 0] = Console.ReadLine();
            Console.Write("please enter the ratings");
            mymatrix[i, 1] = Console.ReadLine();
        }
    }
}

after this i just want to sort an array using ratings,but both names and ratingscan be displayed in outputs..

please help me





      
         
       

 

 

I think the problem here is that you're not really trying to sort a matrix, you're trying to sort an array of tupels. I'd suggest making a class "Item" to hold the Name => Rating mapping.  Then your problem becomes sorting a one dimensional array of Items.  The framework defines a standard interface for things which can be compared : IComparable<T> which your Item class should probably implement. 

Heres a simpler Bubble Sort algorithm. The good thing is that its simple, the bad is that when you use this with a large collection, the performance is incredibly slow. 

// You call the sort() function like this
sort(name, name.Length/2);

// Bubble Sort Algorithm
        public static void sort(string[,] a, int x)
        {
            int i;
            int j;
            string temp;            
            
            for (i = (x - 1); i >= 0; i--)
            {
                for (j = 1; j <= i; j++)
                {                    
                    if (Convert.ToInt32(a[(j - 1), 1]) < Convert.ToInt32(a[j, 1]))
                    {
                        temp = a[j - 1 ,0];
                        a[j - 1, 0] = a[j ,0];
                        a[j ,0] = temp;

                        temp = a[j - 1 ,1];
                        a[j - 1, 1] = a[j, 1];
                        a[j, 1] = temp;
                    }
                }
            }
        }

 

 thanks everyone

i got an error msg 

You have to give more than tha to figure out what the problem is.

here is my code

using System;

class TDMArray
{
    public static void Main()
    {
        string[,] name;
        name = new string[10, 10];


        for (int i = 0; i <= 9; i++)
        {


            Console.Write("Please enter the Names");
          name[i, 0] = Console.ReadLine();
            Console.Write("please enter the ratings");
            name[i, 1] = Console.ReadLine();
        }

       
        sort(name, name.Length / 2);

    }
    public static void sort(string[,] a, int x)
    {
        int i;
        int j;
        string temp;

        for (i = (x - 1); i >= 0; i--)
        {
            for (j = 1; j <= i; j++)
            {
                if (Convert.ToInt32(a[(j - 1), 1]) < Convert.ToInt32(a[j, 1]))
                {
                    temp = a[j - 1, 0];
                    a[j - 1, 0] = a[j, 0];
                    a[j, 0] = temp;

                    temp = a[j - 1, 1];
                    a[j - 1, 1] = a[j, 1];
                    a[j, 1] = temp;
                }
            }
        }
    }
}

and my problem is

Formal Exception was unhandled

input string was not in a correct format..