Informatik-Biber practice in English

1. A coordinator registers. From September a teacher, or another responsible adult at the institution, registers as coordinator at login.bwinf.de. BWINF says no knowledge of informatics is needed for this role.
2. The coordinator enters the pupils. Pupils are added at admin.informatik-biber.de and each gets their own login. BWINF's FAQ says this can be done up to the weekend before the contest.
3. Practice on the real platform. The Schnupper-Biber has been open since 14 September 2026: six tasks in each age group and up to 30 minutes, with the score shown at the end. It closes a few days before the contest.
4. Sit the contest. The Biberwochen 2026 run from 9 to 20 November 2026. The school chooses any day and time within those two weeks, and the contest fits into a single lesson.
5. Results and certificates. BWINF publishes results in December 2026 and sends certificates and prizes in January 2027. Every participant receives a certificate.

Sources: BWINF, Informatik-Biber 2026 page (bwinf.de/biber/2026/), Termine page and Teilnehmen page, read on 2 and 3 November 2026. The order of steps is our own summary of those pages.

from itertools import product

def safe(signal):
    return "11" not in signal

for n in range(3, 8):
    signals = ["".join(s) for s in product("01", repeat=n)]
    good = [s for s in signals if safe(s)]
    print(n, "lanterns:", len(good), "safe signals")
    if n == 4:
        print("  ", " ".join(good))

The program does not think; it simply writes down all sixteen on and off patterns for four lanterns and throws away the ones with two lights together. Eight survive, which agrees with the reasoning. Running it for longer rows shows the numbers 5, 8, 13, 21, 34, each the sum of the two before. Spotting that rule in the output and then explaining why it must hold is exactly the step from checking to understanding that we want a pupil to make.

from itertools import permutations

def can_leave(order):
    tunnel = []
    waiting = [1, 2, 3, 4]
    for beaver in order:
        while beaver not in tunnel and waiting:
            tunnel.append(waiting.pop(0))
        if not tunnel or tunnel[-1] != beaver:
            return False
        tunnel.pop()
    return True

orders = list(permutations([1, 2, 3, 4]))
possible = [o for o in orders if can_leave(o)]
print("Possible exit orders:", len(possible), "of", len(orders))
for test in [(4, 3, 2, 1), (2, 1, 4, 3), (3, 1, 4, 2), (1, 2, 3, 4)]:
    print(test, can_leave(test))

Of the 24 ways four beavers could leave, only 14 are possible through a last-in, first-out tunnel, and 3 1 4 2 is one of the ten that are not. The function copies what the beavers do: let beavers in until the one we want is inside, and fail if it is not the one nearest the exit.

1. Start. Solve all four puzzles on paper and write one sentence on why each answer is right.
2. Check. Run the two programs and compare their output with your answers.
3. Stretch. Change the lantern rule so that three lights may not be on in a row. Predict the count for five lanterns before running the program.
4. Explain. Tell someone at home, in your own words, why the tunnel is a stack and a queue at a bakery is not.

German clocks follow the Einheitenzeitgesetz: UTC+1 since summer time ended on 25 October 2026, and UTC+2 again from 28 March 2027. India keeps UTC+5:30 with no clock change, so a lesson there sits four and a half hours ahead of Germany this winter and three and a half hours ahead in summer.

Treat the rows as samples only; no batch is promised at these exact times. You book the free first class in your own clock, each group keeps the slot its families agreed, and one-to-one lessons shift around school, holidays and the contest weeks.