Problem: Road Construction (CSES) Task: You have cities and roads. You add roads one by one. After each road, report: number of components and size of the largest component.
This is direct DSU application. Track component count (decrement on successful union) and max size (update after union). Output both after each edge. Use union by size so you can track component sizes directly in the DSU array. This problem tests your ability to maintain extra information alongside the DSU structure.