Problems
Every CCC problem the course links, by year. Each one opens on its judge.
2026
| Problem | Title | Taught in |
|---|---|---|
| J1 | Concert Tickets (opens on WMOJ in a new tab) WMOJ | Taught in:M1.4 |
| J2 | Olympic Scores (opens on WMOJ in a new tab) WMOJ | Taught in:M1.2M1.8 |
| J3 | Creative Candy Consumption (opens on WMOJ in a new tab) WMOJ | Taught in:M2.3 |
| J4 | Snail Path (opens on WMOJ in a new tab) WMOJ | Taught in:M2.7 |
| J5 | Beams of Light (opens on WMOJ in a new tab) WMOJ(same problem as 2026 S2) | Taught in:M4.4 |
| S1 | Baby Hop, Giant Hop (opens on WMOJ in a new tab) WMOJ | Taught in:M5.2 |
| S2 | Beams of Light (opens on WMOJ in a new tab) WMOJ | Taught in:M4.4 |
| S3 | Common Card Choice (opens on WMOJ in a new tab) WMOJ | Not in a module yet |
| S4 | Minecarts (opens on WMOJ in a new tab) WMOJ | Taught in:M6.11 |
| S5 | On the Fence (opens on WMOJ in a new tab) WMOJ | Taught in:M7.10 |
2025
| Problem | Title | Taught in |
|---|---|---|
| J1 | Roller Coaster Ride (opens on WMOJ in a new tab) WMOJ | Not in a module yet |
| J2 | Donut Shop (opens on WMOJ in a new tab) WMOJ | Taught in:M1.5 |
| J3 | Product Codes (opens on WMOJ in a new tab) WMOJ | Taught in:M2.2M3.4 |
| J4 | Sunny Days (opens on WMOJ in a new tab) WMOJ | Taught in:M2.9M3.10 |
| J5 | Connecting Territories (opens on WMOJ in a new tab) WMOJ | Not in a module yet |
| S1 | Positioning Peter's Paintings (opens on WMOJ in a new tab) WMOJ | Taught in:M2.6 |
| S2 | Cryptogram Cracking Club (opens on WMOJ in a new tab) WMOJ | Not in a module yet |
| S3 | Pretty Pens (opens on WMOJ in a new tab) WMOJ | Taught in:M5.11 |
| S4 | Floor is Lava (opens on WMOJ in a new tab) WMOJ | Taught in:M5.8M6.1M6.2 |
| S5 | To-Do List (opens on WMOJ in a new tab) WMOJ | Taught in:M7.1M7.11 |
2024
| Problem | Title | Taught in |
|---|---|---|
| J1 | Conveyor Belt Sushi (opens on WMOJ in a new tab) WMOJ | Taught in:M0.7M1.1 |
| J2 | Dusa And The Yobis (opens on WMOJ in a new tab) WMOJ | Taught in:M1.6 |
| J3 | Bronze Count (opens on WMOJ in a new tab) WMOJ | Taught in:M1.13M2.1M2.4M3.3 |
| J4 | Troublesome Keys (opens on WMOJ in a new tab) WMOJ | Taught in:M2.6 |
| J5 | Harvest Waterloo (opens on WMOJ in a new tab) WMOJ | Taught in:M4.13 |
| S1 | Hat Circle (opens on WMOJ in a new tab) WMOJ | Taught in:M2.9M3.5M3.8 |
| S2 | Heavy-Light Composition (opens on WMOJ in a new tab) WMOJ | Not in a module yet |
| S3 | Swipe (opens on WMOJ in a new tab) WMOJ | Taught in:M4.9 |
| S4 | Painting Roads (opens on WMOJ in a new tab) WMOJ | Taught in:M5.7M6.4 |
| S5 | Chocolate Bar Partition (opens on WMOJ in a new tab) WMOJ | Taught in:M7.7 |
2023
| Problem | Title | Taught in |
|---|---|---|
| J1 | Deliv-e-droid (opens on WMOJ in a new tab) WMOJ | Taught in:M1.4 |
| J2 | Chili Peppers (opens on WMOJ in a new tab) WMOJ | Taught in:M1.9M3.5 |
| J3 | Special Event (opens on WMOJ in a new tab) WMOJ | Taught in:M1.8M2.8M3.4 |
| J4 | Trianglane (opens on WMOJ in a new tab) WMOJ(same problem as 2023 S1) | Taught in:M3.7 |
| J5 | CCC Word Hunt (opens on WMOJ in a new tab) WMOJ | Taught in:M1.10 |
| S1 | Trianglane (opens on WMOJ in a new tab) WMOJ | Taught in:M3.7 |
| S2 | Symmetric Mountains (opens on WMOJ in a new tab) WMOJ | Taught in:M5.12 |
| S3 | Palindromic Poster (opens on WMOJ in a new tab) WMOJ | Taught in:M5.1 |
| S4 | Minimum Cost Roads (opens on WMOJ in a new tab) WMOJ | Taught in:M6.1M6.3 |
| S5 | The Filter (opens on WMOJ in a new tab) WMOJ | Taught in:M7.6 |
2022
| Problem | Title | Taught in |
|---|---|---|
| J1 | Cupcake Party (opens on WMOJ in a new tab) WMOJ | Taught in:M1.1M2.7M3.1 |
| J2 | Fergusonball Ratings (opens on WMOJ in a new tab) WMOJ | Taught in:M1.5M3.2M4.8 |
| J3 | Harp Tuning (opens on WMOJ in a new tab) WMOJ | Taught in:M2.1M3.3M4.6 |
| J4 | Good Groups (opens on WMOJ in a new tab) WMOJ(same problem as 2022 S2) | Taught in:M1.9M4.1 |
| J5 | Square Pool (opens on WMOJ in a new tab) WMOJ | Taught in:M4.5M4.14 |
| S1 | Good Fours and Good Fives (opens on WMOJ in a new tab) WMOJ | Taught in:M2.5 |
| S2 | Good Groups (opens on WMOJ in a new tab) WMOJ | Taught in:M1.9M4.1 |
| S3 | Good Samples (opens on WMOJ in a new tab) WMOJ | Taught in:M6.12 |
| S4 | Good Triplets (opens on WMOJ in a new tab) WMOJ | Taught in:M6.9 |
| S5 | Good Influencers (opens on WMOJ in a new tab) WMOJ | Taught in:M6.5 |
2021
| Problem | Title | Taught in |
|---|---|---|
| J1 | Boiling Water (opens on WMOJ in a new tab) WMOJ | Taught in:M1.4M2.6M3.1 |
| J2 | Silent Auction (opens on WMOJ in a new tab) WMOJ | Taught in:M2.4M4.7 |
| J3 | Secret Instructions (opens on WMOJ in a new tab) WMOJ | Taught in:M1.6M3.9 |
| J4 | Arranging Books (opens on WMOJ in a new tab) WMOJ | Taught in:M4.6 |
| J5 | Modern Art (opens on WMOJ in a new tab) WMOJ(same problem as 2021 S2) | Not in a module yet |
| S1 | Crazy Fencing (opens on WMOJ in a new tab) WMOJ | Taught in:M1.11M1.12M3.7M6.13 |
| S2 | Modern Art (opens on WMOJ in a new tab) WMOJ | Not in a module yet |
| S3 | Lunch Concert (opens on WMOJ in a new tab) WMOJ | Taught in:M5.5M5.6 |
| S4 | Daily Commute (opens on WMOJ in a new tab) WMOJ | Taught in:M5.9M5.11 |
| S5 | Math Homework (opens on WMOJ in a new tab) WMOJ | Taught in:M7.3 |
2020
| Problem | Title | Taught in |
|---|---|---|
| J1 | Dog Treats (opens on DMOJ in a new tab) DMOJ | Taught in:M0.7 |
| J2 | Epidemiology (opens on DMOJ in a new tab) DMOJ | Taught in:M1.6M4.1 |
| J3 | Art (opens on DMOJ in a new tab) DMOJ | Taught in:M2.8M3.2 |
| J4 | Cyclic Shifts (opens on DMOJ in a new tab) DMOJ | Taught in:M2.5M4.15 |
| J5 | Escape Room (opens on DMOJ in a new tab) DMOJ(same problem as 2020 S2) | Taught in:M4.13 |
| S1 | Surmising a Sprinter's Speed (opens on DMOJ in a new tab) DMOJ | Taught in:M1.12M3.3M4.2M6.10M6.13 |
| S2 | Escape Room (opens on DMOJ in a new tab) DMOJ | Taught in:M4.13 |
| S3 | Searching for Strings (opens on DMOJ in a new tab) DMOJ | Taught in:M5.3M5.4 |
| S4 | Swapping Seats (opens on DMOJ in a new tab) DMOJ | Taught in:M4.15 |
| S5 | Josh's Double Bacon Deluxe (opens on DMOJ in a new tab) DMOJ | Taught in:M7.5 |
2019
| Problem | Title | Taught in |
|---|---|---|
| J1 | Winning Score (opens on DMOJ in a new tab) DMOJ | Not in a module yet |
| J2 | Time to Decompress (opens on DMOJ in a new tab) DMOJ | Taught in:M1.7M3.2M3.6 |
| J3 | Cold Compress (opens on DMOJ in a new tab) DMOJ | Taught in:M3.4 |
| J4 | Flipper (opens on DMOJ in a new tab) DMOJ(same problem as 2019 S1) | Taught in:M2.9 |
| J5 | Rule of Three (opens on DMOJ in a new tab) DMOJ | Taught in:M4.10M6.10 |
| S1 | Flipper (opens on DMOJ in a new tab) DMOJ | Taught in:M2.9 |
| S2 | Pretty Average Primes (opens on DMOJ in a new tab) DMOJ | Not in a module yet |
| S3 | Arithmetic Square (opens on DMOJ in a new tab) DMOJ | Taught in:M5.1M6.12 |
| S4 | Tourism (opens on DMOJ in a new tab) DMOJ | Taught in:M6.11M6.7M7.12 |
| S5 | Triangle: The Data Structure (opens on DMOJ in a new tab) DMOJ | Taught in:M7.8 |
2018
| Problem | Title | Taught in |
|---|---|---|
| J1 | Telemarketer or not? (opens on DMOJ in a new tab) DMOJ | Not in a module yet |
| J2 | Occupy parking (opens on DMOJ in a new tab) DMOJ | Taught in:M1.7 |
| J3 | Are we there yet? (opens on DMOJ in a new tab) DMOJ | Taught in:M1.11M4.3 |
| J4 | Sunflowers (opens on DMOJ in a new tab) DMOJ(same problem as 2018 S2) | Not in a module yet |
| J5 | Choose your own path (opens on DMOJ in a new tab) DMOJ | Taught in:M4.12M4.13 |
| S1 | Voronoi Villages (opens on DMOJ in a new tab) DMOJ | Taught in:M3.9M4.5 |
| S2 | Sunflowers (opens on DMOJ in a new tab) DMOJ | Not in a module yet |
| S3 | RoboThieves (opens on DMOJ in a new tab) DMOJ | Taught in:M5.9M6.2M7.4 |
| S4 | Balanced Trees (opens on DMOJ in a new tab) DMOJ | Not in a module yet |
| S5 | Maximum Strategic Savings (opens on DMOJ in a new tab) DMOJ | Not in a module yet |
2017
| Problem | Title | Taught in |
|---|---|---|
| J1 | Quadrant Selection (opens on DMOJ in a new tab) DMOJ | Taught in:M1.4 |
| J2 | Shifty Sum (opens on DMOJ in a new tab) DMOJ | Not in a module yet |
| J3 | Exactly Electrical (opens on DMOJ in a new tab) DMOJ | Not in a module yet |
| J4 | Favourite Times (opens on DMOJ in a new tab) DMOJ | Taught in:M3.8 |
| J5 | Nailed It! (opens on DMOJ in a new tab) DMOJ(same problem as 2017 S3) | Taught in:M3.6M6.9 |
| S1 | Sum Game (opens on DMOJ in a new tab) DMOJ | Taught in:M2.4M4.3 |
| S2 | High Tide, Low Tide (opens on DMOJ in a new tab) DMOJ | Taught in:M7.4 |
| S3 | Nailed It! (opens on DMOJ in a new tab) DMOJ | Taught in:M3.6M6.9 |
| S4 | Minimum Cost Flow (opens on DMOJ in a new tab) DMOJ | Taught in:M5.10M6.3 |
| S5 | RMT (opens on DMOJ in a new tab) DMOJ | Taught in:M7.9 |
2016
| Problem | Title | Taught in |
|---|---|---|
| J1 | Tournament Selection (opens on DMOJ in a new tab) DMOJ | Taught in:M1.5 |
| J2 | Magic Squares (opens on DMOJ in a new tab) DMOJ | Taught in:M1.8 |
| J3 | Hidden Palindrome (opens on DMOJ in a new tab) DMOJ | Taught in:M2.5M5.12 |
| J4 | Arrival Time (opens on DMOJ in a new tab) DMOJ | Taught in:M3.5 |
| J5 | Tandem Bicycle (opens on DMOJ in a new tab) DMOJ(same problem as 2016 S2) | Taught in:M4.2 |
| S1 | Ragaman (opens on DMOJ in a new tab) DMOJ | Taught in:M1.13M3.6 |
| S2 | Tandem Bicycle (opens on DMOJ in a new tab) DMOJ | Taught in:M4.2 |
| S3 | Phonomenal Reviews (opens on DMOJ in a new tab) DMOJ | Taught in:M5.7M5.8 |
| S4 | Combining Riceballs (opens on DMOJ in a new tab) DMOJ | Taught in:M6.6 |
| S5 | Circle of Life (opens on DMOJ in a new tab) DMOJ | Not in a module yet |
2015
| Problem | Title | Taught in |
|---|---|---|
| J1 | Special Day (opens on DMOJ in a new tab) DMOJ | Not in a module yet |
| J2 | Happy or Sad (opens on DMOJ in a new tab) DMOJ | Taught in:M1.7 |
| J3 | Rövarspråket (opens on DMOJ in a new tab) DMOJ | Not in a module yet |
| J4 | Wait Time (opens on DMOJ in a new tab) DMOJ | Taught in:M2.3M4.14 |
| J5 | π-day (opens on DMOJ in a new tab) DMOJ | Taught in:M1.14M4.11 |
| S1 | Zero That Out (opens on DMOJ in a new tab) DMOJ | Not in a module yet |
| S2 | Jerseys (opens on DMOJ in a new tab) DMOJ | Taught in:M3.10 |
| S3 | Gates (opens on DMOJ in a new tab) DMOJ | Taught in:M5.10 |
| S4 | Convex Hull (opens on DMOJ in a new tab) DMOJ | Taught in:M6.1 |
| S5 | Greedy For Pies (opens on DMOJ in a new tab) DMOJ | Taught in:M6.7M7.12 |
2014
| Problem | Title | Taught in |
|---|---|---|
| J1 | Triangle Times (opens on DMOJ in a new tab) DMOJ | Taught in:M3.1 |
| J2 | Vote Count (opens on DMOJ in a new tab) DMOJ | Not in a module yet |
| J3 | Double Dice (opens on DMOJ in a new tab) DMOJ | Taught in:M2.3 |
| J4 | Party Invitation (opens on DMOJ in a new tab) DMOJ(same problem as 2014 S1) | Taught in:M2.2 |
| J5 | Assigning Partners (opens on DMOJ in a new tab) DMOJ(same problem as 2014 S2) | Taught in:M1.9M4.1 |
| S1 | Party Invitation (opens on DMOJ in a new tab) DMOJ | Taught in:M2.2 |
| S2 | Assigning Partners (opens on DMOJ in a new tab) DMOJ | Taught in:M1.9M4.1 |
| S3 | The Geneva Confection (opens on DMOJ in a new tab) DMOJ | Not in a module yet |
| S4 | Tinted Glass Window (opens on DMOJ in a new tab) DMOJ | Taught in:M6.8 |
| S5 | Lazy Fox (opens on DMOJ in a new tab) DMOJ | Not in a module yet |