Donald Knuth algorithm for Mastermind - c

Question

I'm working onto the Donald Knuth 1977 algorithm for Mastermind (here). I've implemented some steps, but I don't know how to calculate the number of possibilites that would be eliminated for each possible score.
Integer Bulls <- 0
WHILE Bulls <= 4
Integer Cows <- 0
WHILE Cows <= 4
Integer CurrentSetSize <- 0
WHILE CurrentSetSize <= Set.size
// Now, I should know if this possibility can be eliminated. But how ?
END WHILE
END WHILE
END WHILE
Do you have any way to do this ?
Thanks.
Edit : I did it with C. It isn't Mastermind in reality but Bulls & Cows, but it's the same.
// ASCII-compatible
#define POSSIBILITIES 6720
struct Guess {
int i[5];
};
struct Answer {
int bulls;
int cows;
};
static struct Set {
struct Guess value;
int score;
} *CurrentSet;
void
initSet(void)
{
for (int i = 'a'; i <= 'h'; ++i) {
for (int j = 'a'; j <= 'h'; ++j) {
if (j == i) continue;
for (int k = 'a'; k <= 'h'; ++k) {
if (k == j || k == i) continue;
for (int l = 'a'; l <= 'h'; ++l) {
if (l == k || l == j || l == i) continue;
for (int m = 'a'; m <= 'h'; ++m) {
if (m == l || m == k || m == j || m == i) continue;
CurrentSet->value.i[0] = i;
CurrentSet->value.i[1] = j;
CurrentSet->value.i[2] = k;
CurrentSet->value.i[3] = l;
CurrentSet->value.i[4] = m;
CurrentSet->score = 0;
}
}
}
}
}
}
void
computeScore(int index)
{
struct answer p;
for (p.bulls = 0; p.bulls <= 4; ++p.bulls) {
for (p.cows = 0; p.cows <= 4; ++p.cows) {
for (int i = 0; i < POSSIBILITIES; ++i) {
}
}
}
}
void
updateSet(void)
{
for (int i = 0; i < POSSIBILITIES; ++i)
computeScore(i);
}