Question

So I have the following homework, but I don’t understand exactly what the process is. Has anyone seen this question before or actually understands what the logic should be? I don’t want code, I know how to program, but I don’t exactly know what to do here.

Consider a wire across which data is transmitted bit-by-bit. Occasionally, a bit or a group of
consecutive bits is transmitted incorrectly. If the previous bit was transmitted correctly, the
probability that the current bit is transmitted incorrectly is 0.1. If the previous bit was
transmitted incorrectly, the probability that the current bit is also transmitted incorrectly
is 0.3. Write a program called BitError.java that simulates the transmission of one million
bits and prints out the percentage of bits transmitted incorrectly.
(Hint: According to theory, the expected answer is 12.5%.)

Answer 1

You test for the probability of an event happening as follows

1. Generate a uniform random number between 0 and 1
2. If the number generated is less than the prob an event happening then the event happend

Your code should look something like this

// Generate random bit either a 0 or a 1
int bit = RandInt(0,1)

// Assume first bit was correct
bool bPreviousWasCorrect = false;

Loop 1 million times
    double probBitIsCorrect = RandUnif(0,1) // get a random number between 0 and 1
    if bPreviousWasWrong then
        // if an error has occured then a 2nd error occurs with prob 0.3
        if (probBitIsCorrect < 0.3)  then
           Set bPreviousWasWrong to true
           increment number of wrong bits
        else
           Set bPreviousWasWrong to false
           increment number of correct bits
        end if
    else
        if (probBitIsCorrect < 0.1)  then
           Set bPreviousWasWrong to true
           increment number of wrong bits
        else
           Set bPreviousWasWrong to false
           increment number of correct bits
        end if

Display results when done