### Rei's blog

By Rei, 9 years ago, translation, ,
Problem B.
One just needs to calculate all possible answers and find the minimum. For example one may run on a set of numbers, for all pairs of numbers apply next operation to that pair and recursively run on a new set of numbers. When only one number remains, compare it to the already obtained minimum, and change that minimum if  it's needed.

• +19

 9 years ago, # |   0 Can you describe how the answer to 1st test is 3?1 1 1 1+ + *i proceed this way+2 2 1 1+2 3 3 1*2 3 3 3???
•  9 years ago, # ^ |   +5 Read the problem statement carefully. The operations are:1 1 1 1+2 1 1+3 1*3
•  9 years ago, # ^ | ← Rev. 2 →   +5 I think you didn't understand the statement correctly. "... replaced them with their sum or their product." means that he erases two numbers and writes only one (sum or product). I see ambiguity in mentioned phrase, but you can derive right interpretation from the next sentence: "In the end he got one number". So after 3 minutes there should be only one number at the blackboard.In 1st test we have:1 1 1 1+2 1 1+3 1*3We apologize for that ambiguity, but believe that it is not very hard to resolve it by reading statement carefully one more time.Meh, I am too slow.
 9 years ago, # |   0 Thanks!i thought "them" in the problem statement refered both of the numbers.