Balti Tee 2019 · Ülesanne 8
Kombinatoorika
There are 2019 cities in the country of Balticwayland. Some pairs of cities are connected by non-intersecting bidirectional roads, each road connecting exactly 2 cities. It is known that for every pair of cities and it is possible to drive from to using at most 2 roads. There are 62 cops trying to catch a robber. The cops and robber all know each others' locations at all times. Each night, the robber can choose to stay in her current city or move to a neighbouring city via a direct road. Each day, each cop has the same choice of staying or moving, and they coordinate their actions. The robber is caught if she is in the same city as a cop at any time. Prove that the cops can always catch the robber.
Kui oled valmis
Ülevaatematerjal muutub kättesaadavaks järgmise päevaülesannete komplektiga.
Ülevaade
Teemad
Mängud ja strateegiad · Loendamine · Dirichlet’ printsiip ja ekstremaalargumendid
Lahendused
Kontrollitud kohalik lahendus ei ole praegu saadaval.
Võistluse kontekst
Balti Tee tulemused 2019
11 võistkonda
- Keskmine tulemus
- 1,9 / 5
- 4 või 5 punkti
- 3 / 11
- Eesti
- 0 / 5
Punktijaotus
Kõigi võistkondade punktid
| Võistkond | Punktid |
|---|---|
| St. Petersburg | 2 / 5 |
| Poland | 2 / 5 |
| Estonia | 0 / 5 |
| Lithuania | 2 / 5 |
| Germany | 5 / 5 |
| Norway | 0 / 5 |
| Finland | 5 / 5 |
| Denmark | 0 / 5 |
| Sweden | 0 / 5 |
| Latvia | 5 / 5 |
| Iceland | 0 / 5 |