Greedy

Sort intervals by start, then sweep left to right: extend the current interval when the next overlaps, otherwise close it and begin a new one.

Sort meetings by start, use a min-heap of end times to free finished rooms before each meeting, and the peak heap size is the room count.

The minimum cost to stand on a step is its fee plus the cheaper of the two steps below; the top is reached by taking the cheaper of the last two steps.

Use a min-heap keyed on capital requirement and a max-heap keyed on profit; each round unlock affordable projects and greedily pick the most profitable one.

Use two max-heaps (by end and by start); process the latest-ending interval first, then pop starts to find the smallest start that covers that end.

Sort by start, sweep left to right, extend the current interval on overlap using max-end, and start a new interval on a gap.

The overlap of two intervals is max-start to min-end; advance the pointer of whichever interval ends first.

Sort by start, then check if any interval starts before the previous one ends; if so, there is an overlap.

Give change using the largest notes first to hoard the scarce small notes.

Track the farthest reachable index; if an index passes it, you are stuck.

Sort both sides and give each claimant the smallest resource that still satisfies them.

Track farthest reach; if i > reach you are stuck; else extend reach.