My hacked solution: https://codeforces.com/contest/1132/submission/50838954

On the worst possible test (test 52):

5000 5000
1 5000
...
1 5000

It just barely passes with >255 mb used. Memory usage is high beceause I fill all of those 5000 vectors with as much as data possible. However, a slightly different test (generated hack):

5000 5000
(randomly choose 1 or 2) 5000
...

Causes MLE. How could this be? Is it possible that generator affects memory usage? It MLE on that same hack upon resubmit though.