Hi, everyone! I need some problems, which can be solved with Persistent data structures (It doens't matter what data structure as long as it is persistent). I searched but the only thing that I was able to find was this — http://blog.anudeep2011.com/persistent-segment-trees-explained-with-spoj-problems/ . There are like 5 problems, so I need more. I will be very glad if you could find me some. I need at least 4 or 5, so anything would be in help. Thank you!