Brute force implementation of the eight queens problem

queen8.py

def bf_queen(m):
    return bf_queen_rec(m, 0)


def check(r, v):
    pos_1, pos_2 = v, v
    for j in r:
        pos_1 = pos_1 - 1
        if m[j] == pos_1:
            return False

        pos_2 = pos_2 + 1
        if m[j] == pos_2:
            return False

    return True


def win(m):
    if len(set(m)) < 8:
        return False

    for i in range(0, 8):
        before = range(i - 1, 0, -1)
        after = range(i + 1, 8)

        if not check(before, m[i]) or not check(after, m[i]):
            return False

    return True


def bf_queen_rec(m, col):
    if col > 7:
        return

    for i in range(0, 7):
        bf_queen_rec(m, col + 1)

        if win(m):
            return m
        else:
            m[col] = m[col] + 1

    m[col] = 1


# m = [1] * 8
m = [5, 1, 8, 4, 2, 6, 2, 6] # the solution is 5, 1, 8, 4, 2, 7!!!, 3!!!, 6
solution = bf_queen(m)
print(solution)