C# using 2 arrays, count how many times numbers appear in an array

Question

So yeah, current assignment was to make a program that asks the user to input numbers. When they quit, display a histogram of the number of times they entered numbers

Requirements Numbers are 0-10. User can quit any time Make it that the user can enter as many numbers as they want. Display it like If they entered 1,0,0,0,2,2,3,4,4,4,5 0*** 1* 2** 3* 4*** 5*

So i had worked on this, and got a working version of it before finding out i had misread the program. I thought I only needed to have 10 entries, and display that. Got that working. Then i found out it should be unlimited entries basically. We should be using two arrays. One for the numbers 0-10 and one for the counts. Should be in a for loop.

I think that since i got what i thought was what i needed done, my brain is blanking on how to do this.

My assumptions is something like

array[11]{0, 1,2,3,4,5,6,7,8,9,10) count[11]{0,0,0,0,0,0,0,0,0,0,0}

Then ask for user input, check the number, if its a 0, then increase the index 0 value of count by 1. If its a 1, increase the index of count by 1 and up its value by 1. Etc

I dont want to make a bunch of if statements, and I cannot for the life of me think of how i would call the index for a value for displaying. If i want to see what the value of Index+3 (so, how many times 3 was entered) how do i display it.

This is my old code, i do have a class for the things i call to. GetInput and OutputMessage are just methods using the console read and writeline code.

I cannot use dictionaries, or lists. I dont think 2 arrays is required.

Thank you for any help given.

    static public void Myhistogram()
    {
        Histogram myInstanceofDisplayNumbers = new Histogram();
        AverageArray myInstanceofHighLowAverage = new AverageArray();
        ArrayInputAndSort myInstanceofArrayInputAndSort = new ArrayInputAndSort();

        try
        {
            InputOutput.OutputMessage("Enter 10 numbers from 0-10");

            int[] numbers = new int[10] {0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
            int[] counts = new int[10] {0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
            int count = 0;
            bool entrycompleted = false;
            string input = "a";

            while (!entrycompleted)
            {

                input = InputOutput.GetInput(string.Format("Entry {0}", count + 1));
                int result;
                if (int.TryParse(input, out result) == false && input.ToLower() != "q" || int.Parse(input) < 0)
                {
                    InputOutput.OutputMessage("Please enter a number from 0-9");

                }
                else
                {
                    if (input == String.Empty)
                    {
                        InputOutput.OutputMessage("Entry was blank");
                    }
                    else if (input == "q")
                    {
                        InputOutput.OutputMessage("Sorry no quitting until all 10 numbers entered");

                    }





                    else
                    {
                        if (int.TryParse(input, out result))
                            //result is the number inputted by the user, it will be asked if its greater or equal to 0, and less than or equal to 10. 
                            // if it is, follow through, otherwise, invalid entry. 
                        {
                            if (result >= 0 && result <= 10)
                            {
                                // numbers is my inputted array
                                numbers[count] = result;



                                if (count > 10)
                                {
                                    entrycompleted = true;
                                }
                            }
                            else
                            {
                                InputOutput.OutputMessage("Invalid entry. Try again.");
                            }

                        }
                        else
                        {
                            entrycompleted = true;
                        }

                    }
                }
            }
            InputOutput.OutputMessage("");

            myInstanceofArrayInputAndSort.SortNumbers(numbers.Length, numbers);
            myInstanceofDisplayNumbers.DisplayHistogram(numbers, count, counts);

        }
        catch (Exception ex)
        {
            //OutputMessage is a static method of the class
            //InputOutput therefore you DO NOT need your own
            //instance; INSTEAD reference using the classname
            InputOutput.OutputMessage(ex.Message);
        }

    }

    public void DisplayHistogram(int[] numbers, int count, int[] counts)
    {

       // int[] frequencyofintegers = new int[10];


        for (int i = 0; i < count; i++)
        {
            counts[numbers[i]]++;
        }

        for (int i = 0; i <= 10; i++)
        {
            if (counts[i] == 0)
            {

            }
            else
            {

                InputOutput.OutputSameLine(string.Format("{0}: ", i));

                for (int j = 0; j < counts[i]; j++)
                {
                    InputOutput.OutputSameLine("*");
                }

                InputOutput.OutputMessage("");
            }
        }

        InputOutput.OutputMessage("");
    }

Answer 1

Since the requirements allow 0-10, you already have your indexes! You don't need an second array, dictionary or anything else.

So your input read looks like (simplified):

counts[int.Parse(Console.ReadLine())]++; //Probably should use TryParse!

To print them out, just loop:

for (int i = 0; i < 11; i++)
   Console.WriteLine("{0}, {1}", i, counts[i]);

To get a specific count, its just counts[i]