interval problems (ranges with start/end)s are ranges defined by start and end points. You process them by sorting and then scanning to detect overlaps, merge, or count. Sorting by start (or end) enables linear processing of interval relationships. Most interval problems reduce to: sort, then process pairs of adjacent intervals.
You'll see this in scheduling and range merging problems. Understanding these concepts deeply helps you solve related problems faster. Take time to internalize the pattern.
