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Illustrating the probability distribution.

★★★

If a computer's random number generator is providing an accurate distribution of numbers, when you simulate the roll of two dice and record the sum, you should achieve a triangular curve in the result of a thousand rolls. This program illustrates the output of the random number generating algorithm used by the Random class in C#.

Distribution of two dice

Make

Write a program that outputs the number of 2’s, 3’s, 4’s etc. that are rolled by adding two random numbers between one and six. The number of rolls to simulate is input by the user.

Success Criteria

Remember to add a comment before a subprogram, selection or iteration statement to explain its purpose.

Complete the subprogram called distribution that:

  1. Takes one argument, the number of two dice rolls to simulate.
  2. Rolls two dice, sums them together and adds the result to a tally. E.g. If a four and three are rolled the sum is seven, so the tally for the number seven is increased by one.
  3. Outputs the results for the eleven possible rolls, two to twelve.

Complete the main program so that:

  1. The user can input how many rolls to simulate.
  2. It calls the distribution subprogram.

Typical inputs and outputs from the program would be:

How many rolls to simulate? :
2 : 34
3 : 61
4 : 82
5 : 131
6 : 147
7 : 168
8 : 130
9 : 101
10 : 79
11 : 44
12 : 23
🆘 If you're really stuck, use this Parsons code sorting exercise
Complete program
// Distribution of two dice program

using System;

class Submission
{
---
    // -------------------------
    // Globals
    // -------------------------
    static Random random_generator = new Random();
---


    // -------------------------
    // Subprograms
    // -------------------------
    static void distribution(int rolls)
    {
---
        // Initialise dice and results
        int[] dice = {0, 0};
        int[] result = new int[13];
---
        for (int roll = 0; roll < 13; roll++)
        {
---
            result[roll] = 0;
---
        }
---

        // Simulate dice rolls
        for (int counter = 0; counter < rolls; counter++)
        {
---
            dice[0] = random_generator.Next(1, 7);
            dice[1] = random_generator.Next(1, 7);
---
            int sum = dice[0] + dice[1];
---
            result[sum] += 1;
---
        }
---

        // Output result
        for (int roll = 2; roll < result.Length; roll++)
        {
---
            Console.WriteLine($"{roll} : {result[roll]}");
---
        }
---
    }


---
    // -------------------------
    // Main program
    // -------------------------
    public static void Main(string[] args)
    {
---
        Console.WriteLine("How many rolls to simulate? :");
        int rolls = Convert.ToInt32(Console.ReadLine());
---
        distribution(rolls);
---
    }
}