Hello everyone, I came up with this problem and I can't figure a solution out. I don't know if it has appeared before.
You are given a matrix of size n × m. Answer two types of queries:
- 1 k i1 i2 ... ik: Set the active set to {i1, i2, ..., ik}.
- 2 x: What is the value of ai1, x + ai2, x + ... + aik, x, where i1, i2, ..., ik are the current elements in the active set?
There are less than n queries of type 1, and less than m queries of type 2 between a pair of queries of type 1.
1 \leq n, m \leq 2000$, however solutions with any reasonable complexity are welcome.
Also, if a query of type 1 appears for the i-th time, 1 \leq k \leq i.