Question 4
After a snowstorm, three beavers are trapped at home. A robot must rescue them by going to the front doors of their homes.
The roads are covered with snow, making travel difficult. The robot needs 2 hours to travel through each square, but only 1 hour through squares it has already visited. It can move horizontally and vertically, but not diagonally. What is the minimum number of hours needed to rescue the beavers and return to the starting square?
The roads are covered with snow, making travel difficult. The robot needs 2 hours to travel through each square, but only 1 hour through squares it has already visited. It can move horizontally and vertically, but not diagonally. What is the minimum number of hours needed to rescue the beavers and return to the starting square?