Generate all polynomials with coefficients 0 or 1 given degree n

Question

I am trying to enumerate in 'C#' all the possible polynomials given the degree. Is there any algorithm to enumerate all possible polynomials given degree n? Maybe I don't know how to ask this question precisely but these are the examples:

For example:

for n=1:

x+1    return [1 1]
x      return [1 0]

for n=2:

x^2+x+1  return [1 1 1]
x^2+x    return [1 1 0] 
x^2      return [1 0 0]
x^2+1    return [1 0 1] 

for n=3:

x^3           return [1 0 0 0]
x^3+x^2       return [1 1 0 0]
x^3+x         return [1 0 1 0]
x^3+x^2+x     return [1 1 1 0]
x^3+1         return [1 0 0 1]
x^3+x^2+1     return [1 1 0 1]
x^3+x+1       return [1 0 1 1]
x^3+x^2+x+1   return [1 1 1 1]

Any pseudo code or algorithm would help.

Answer 1

Set the leftmost bit, then do a binary counter on the right n bits. You actually need n+1 bits to account for x^0, (in my first attempt I was off by 1).

You can generate an enumeration like so:

IEnumerable<int[]> GenPolys(int n)
{
    int[] a = new int[n + 1];
    a[0] = 1;
    bool ok = true;
    while (ok)
    {
        yield return a;
        ok = false;
        for (int i = 1; i < a.Length; i++)
        {
            a[i] = 1 - a[i]; // flip the ith bit
            if (a[i] == 1)
            {
                ok = true;
                break;
            }
        }
    }
}

Usage:

foreach (int[] poly in GenPolys(4))
{
    // your code here
}