CTK Insights

In their textbook Discrete Algorithmic Mathematics authors Stephen Maurer and Anthony Ralston offer a light-hearted example [pp. 217-221]: When checking into a hotel nowadays, sometimes a guest receives a four-digit "combination", not a key. On the door of each room is a keypad. Any time those four digits are entered in the proper sequence (regardless [...]

In chapter 7 of his book Number-Crunching Paul Nahin treats a "Leapfrog" problem posed by M. Schwartz from Ventura, CA, to Marylin von Savant in her "Ask Marylin" column: A friend and I once went from his house to mine with one bike. I started walking and he rode the bike. When he got a [...]