The extended Grind list: starts with confidence-building easies, ramps into mediums week by week, and finishes in hard territory. Follow it in order — the sequencing (difficulty, topic variety, spaced repetition of patterns) is the point. Adapted to the problems available in the Solvarch catalog.
Easy problems that establish the core data structures.
Get the boundaries right without thinking.
Each of these hides a technique you'll reuse for years.
Boyer–Moore voting.
Fast/slow pointers.
Extended-list easies: close every fundamentals gap.
Merge from the back for O(1) space.
Heap vs quickselect trade-offs.
Union-find.
Dijkstra.
Binary search on answers, and the classic hards.
MST — Prim or Kruskal.