DRILLS

Games

Short, stubborn exercises. They teach the invariant, not a high score table.

• G1 · Foundations · 6 min

  Complexity Clash

  Name the Big-O before the clock names you.

• G2 · Core Techniques · 8 min

  Pointer Duel

  Move L and R. Trust the invariant.

• G3 · Core Techniques · 7 min

  Monotonic Oracle

  Find the first true. Spend log n probes.

• G4 · Graphs & Search · 8 min

  Flood Fill Lab

  Watch BFS paint a component.

• G5 · Foundations · 6 min

  Index Jenga

  Pull the wrong index and the range collapses.

• G6 · Core Techniques · 8 min

  Window Snake

  Expand R, drop L. Watch the sum payload.

• G7 · Graphs & Search · 8 min

  Shortest Maze

  Watch BFS distances flood from start to exit.