Задача 8 ферзей (Las Vegas)

from random import randint

sols = []

def f(k, e):
    if k == 8:
        if e not in sols:
            sols.append(e)
        return True
    candidates = []
    for i in range(8):
        for x, y in e:
            if x == i or abs(y - k) == abs(x - i):
                break
        else:
            candidates.append((i, k))
    if candidates:
        e.append(candidates[randint(0, len(candidates) - 1)])
        res = f(k + 1, e)
        if res:
            return True
    return False

def main():
    while len(sols) != 92:
        f(0, [])

    for s in sols:
        print(s)
        for x, _ in s:
            print(('-' * x) + '*' + ('-' * (7 - x)))

main()