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IOI Checkpoint / Score-Path Drill 01

Goal:

  • practice banking a real safe score path before gambling on the full solution

Time budget:

  • 90-110 minutes

Entry gate:

  • you already know the core topic family well enough that the main bottleneck is proof, checkpointing, or subtask planning

Inputs:

Output artifacts:

  • one filled worksheet
  • one bank / upgrade / park decision
  • one short debrief naming the first false assumption

Use This When

  • you keep seeing the full idea too late
  • you often lose safe partial points while chasing the full route
  • your post-contest notes say “I almost had it” without identifying which checkpoint was actually safe

Good Repo Anchors

If none of those fit the family you want, take one official task and keep the same protocol.

Session Script

0-10 min: Read And Fill The Buckets

  • read the statement and visible subtask or score structure
  • fill every row of the IOI Subtask-First Worksheet without coding
  • write the smallest valid algorithm for each visible bucket before thinking about the full solution

10-20 min: Choose The Safest Score Path

  • select one current target bucket
  • complete only the worksheet's Current Target Proof Gate
  • if that proof gate still feels vague, downshift to the safest bucket you can actually prove

20-60 min: Implement Only The Checkpoint

  • code the chosen score path only
  • do not “half-build” the full solution during this phase
  • keep one compiling checkpoint at all times

60-75 min: Validate At The Boundary

75-90 min: Decide Bank / Upgrade / Park

  • bank if the checkpoint is proved and stable
  • upgrade only if the next bucket is adjacent and the proof delta is concrete
  • park if the next route is still intuition-only or validation is unstable

90-100 min: Debrief

Log exactly:

  1. highest proven score path
  2. safe checkpoint actually banked
  3. first false assumption
  4. next repo door

Success Criteria

  • you banked one route that you could explain and validate cleanly
  • your next action is explicit: upgrade, topic review, validation fix, or park
  • the first false assumption was caught before it consumed the entire session

Failure Routing

Failure signal Go next
proof still fuzzy Reasoning
validation is the real bottleneck Stress Testing Workflow or Local Judge Workflow
implementation blocked a known idea Build Kit
topic depth was weaker than expected the corresponding Topic page, then the matching Ladder

After This Drill

  • return to IOI / OI Playbook if the track logic still fits
  • reopen Problem Finder if you want the next official-style rep
  • go back to Mixed Rounds only if the real bottleneck is switching rather than proof discipline

Research snapshot refreshed against official IOI sources on 2026-04-24.