I'm attempting to solve https://cses.fi/problemset/task/2168, and I believe I have the right idea, but i'm failing all large test cases. My algorithm is to:

1. Transform inputs so that they're constrained to the range [0,400000]
2. For every interval start, keep track of the smallest and largest interval ending.
3. Build a sparse table to solve Range Minimum Queries on the minimum array.
4. Build simpler (cheaper) array to RMQ with L=1 fixed.
5. Finally itterate through all queries and solve (one $$$O(1)$$$ call to the sparse table per query.)

Implementation: https://cses.fi/paste/cec69737a6649398283c56/

My main thought is to use an offline query method instead, but nothing here seems like it should exceed the 1 second time limit.