Problems
| Problem Name | Code | Points | Users | AC Rate | Date Added |
|---|---|---|---|---|---|
| NOI '97 - Competition Ranking | noi97p1 | 7 | 28 | 28.36% | 2014-04-27 |
| NOI '97 - Optimal Routing | noi97p2 | 12p | 42 | 26.70% | 2014-04-27 |
| NOI '97 - File Matching | noi97p3 | 25p | 0 | 0.00% | 2014-04-27 |
| NOI '97 - Perfect Tour | noi97p4 | 5 | 99 | 31.17% | 2014-04-27 |
| NOI '97 - Building Game | noi97p5 | 15p | 16 | 22.99% | 2014-04-27 |
| NOI '97 - Satellite Coverage | noi97p6 | 17p | 17 | 37.50% | 2014-04-27 |
| NOI '98 - Personal Income Tax | noi98p1 | 7 | 10 | 52.00% | 2014-05-01 |
| NOI '98 - Free Pizza | noi98p2 | 15p | 7 | 13.79% | 2014-05-01 |
| NOI '98 - Software Installation Disk | noi98p3 | 15p | 4 | 56.25% | 2014-05-01 |
| NOI '98 - Scarf Cutting | noi98p4 | 15p | 4 | 26.67% | 2014-05-01 |
| NOI '98 - SERNET Simulation | noi98p5 | 12p | 7 | 7.38% | 2014-05-01 |
| NOI '98 - Parallel Computing | noi98p6 | 25p | 0 | 0.00% | 2014-05-01 |
| NOI '99 - 01 Sequence | noi99p1 | 20p | 7 | 20.51% | 2014-05-04 |
| NOI '99 - Nails and Ball | noi99p2 | 15p | 6 | 13.64% | 2014-05-04 |
| NOI '99 - Birthday Cake | noi99p3 | 20p | 2 | 5.00% | 2014-05-04 |
| NOI '99 - Chessboard Division | noi99p4 | 15p | 5 | 19.23% | 2014-05-04 |
| NOI '99 - Optimally Connected Subset | noi99p5 | 15p | 11 | 84.62% | 2014-05-04 |
| NOI '99 - Memory Allocation | noi99p6 | 20p | 2 | 20.00% | 2014-05-04 |
| NOI '00 - Ceramic Necklace | noi00p1 | 5 | 30 | 27.42% | 2014-05-06 |
| NOI '00 - Program Parser | noi00p2 | 12p | 6 | 16.18% | 2014-05-06 |
| NOI '00 - Mystery of the Lost City | noi00p3 | 17p | 4 | 35.71% | 2014-05-06 |
| NOI '00 - Trie | noi00p4 | 7 | 70 | 51.60% | 2014-05-06 |
| NOI '00 - Frogs Crossing the River | noi00p5 | 10 | 62 | 30.67% | 2014-05-06 |
| NOI '00 - Symbol Deciphering | noi00p6 | 40p | 0 | 0.00% | 2014-05-06 |
| NOI '01 - Food Chain | noi01p1 | 15p | 23 | 19.61% | 2014-05-08 |
| NOI '01 - Artillery Positioning | noi01p2 | 20p | 20 | 20.59% | 2014-05-08 |
| NOI '01 - The Clever Typist | noi01p3 | 15p | 14 | 28.79% | 2014-05-08 |
| NOI '01 - Applications of Arctangent | noi01p4 | 15 | 28 | 19.00% | 2014-05-08 |
| NOI '01 - Equation Solutions | noi01p5 | 15p | 25 | 13.99% | 2014-05-08 |
| NOI '01 - Secret of the Meteorite | noi01p6 | 20p | 10 | 35.48% | 2014-05-08 |
| NOI '02 - Legend of the Galactic Heroes | noi02p1 | 15p | 48 | 22.00% | 2014-05-11 |
| NOI '02 - The Greedy Kuzuryū | noi02p3 | 25p | 33 | 21.51% | 2014-05-11 |
| NOI '02 - Island of Cavemen | noi02p4 | 20p | 11 | 12.70% | 2014-05-11 |
| NOI '02 - New Tetris | noi02p5 | 30p | 2 | 66.67% | 2014-05-11 |
| NOI '02 - Robot No. M | noi02p6 | 25p | 11 | 70.83% | 2014-05-11 |
| NOI '03 - Stick Game | noi03p1 | 15p | 4 | 36.36% | 2014-05-16 |
| NOI '03 - Text Editor | noi03p2 | 30p | 13 | 31.40% | 2014-05-16 |
| NOI '03 - Data Generator | noi03p4 | 20p | 22 | 18.18% | 2014-05-17 |
| NOI '03 - ZPLHZ | noi03p6 | 25p | 1 | 1.85% | 2014-05-18 |
| NOI '04 - The Depressed Cashier | noi04p1 | 20p | 41 | 11.85% | 2014-05-19 |
| NOI '04 - Manhattan | noi04p3 | 25p | 7 | 12.90% | 2014-05-19 |
| NOI '04 - Rainfall | noi04p4 | 25p | 2 | 20.00% | 2014-05-19 |
| NOI '04 - Little H's Little Hut | noi04p5 | 20p | 1 | 25.00% | 2014-05-19 |
| NOI '05 - The Magnificent Waltz | noi05p1 | 20p | 19 | 29.73% | 2014-06-02 |
| NOI '05 - Maintaining a Sequence | noi05p2 | 40p | 33 | 28.26% | 2014-06-02 |
| NOI '05 - Wisdom Beads Game | noi05p3 | 40p | 4 | 18.52% | 2014-06-02 |
| NOI '05 - CongCong and KoKo | noi05p4 | 20p | 26 | 19.38% | 2014-06-02 |
| NOI '05 - Little H's Party | noi05p5 | 30p | 1 | 2.76% | 2014-06-02 |
| NOI '05 - Lemon Tree Under the Moon | noi05p6 | 50p | 2 | 30.00% | 2014-06-02 |
| NOI '06 - Network Charges | noi06p1 | 20p | 14 | 24.39% | 2014-07-23 |
| NOI '06 - Millennium Worm | noi06p3 | 25p | 4 | 19.35% | 2014-07-23 |
| NOI '06 - Maximum Profit | noi06p4 | 20p | 35 | 21.59% | 2014-07-23 |
| NOI '06 - The Clever Tour Guide | noi06p5 | 30p | 3 | 2.90% | 2014-07-23 |
| NOI '06 - The Magical Bag | noi06p6 | 20p | 3 | 15.38% | 2014-07-24 |
| NOI '07 - Social Network | noi07p1 | 15p | 49 | 26.70% | 2014-07-24 |
| NOI '07 - Cash Exchange | noi07p2 | 30p | 12 | 8.46% | 2014-07-25 |
| NOI '07 - Surrounding Battalions | noi07p3 | 40p | 0 | 0.00% | 2014-07-26 |
| NOI '07 - Necklace Factory | noi07p4 | 30p | 18 | 13.31% | 2014-07-27 |
| NOI '07 - Counting Spanning Trees | noi07p5 | 30p | 5 | 10.34% | 2014-07-27 |
| NOI '07 - Thief Catching | noi07p6 | 40p | 0 | 0.00% | 2014-07-28 |
| NOI '08 - Masquerade Party | noi08p1 | 25p | 13 | 7.57% | 2014-08-01 |
| NOI '08 - Course Design | noi08p2 | 30p | 7 | 3.35% | 2014-08-01 |
| NOI '08 - Hiring Employees | noi08p3 | 25p | 22 | 40.70% | 2014-08-01 |
| NOI '08 - Olympic Logistics | noi08p4 | 25p | 7 | 23.68% | 2014-08-01 |
| NOI '08 - Candy Rain | noi08p5 | 30p | 7 | 9.72% | 2014-08-01 |
| NOI '08 - Tournament Matching | noi08p6 | 40p | 1 | 1.06% | 2014-08-01 |
| NOI '09 - Transformed Sequence | noi09p1 | 20p | 16 | 25.37% | 2014-08-04 |
| NOI '09 - Little G the Poet | noi09p2 | 25p | 6 | 6.54% | 2014-08-04 |
| NOI '09 - Modified Treap | noi09p3 | 20p | 16 | 18.87% | 2014-08-04 |
| NOI '09 - Plants vs. Zombies | noi09p4 | 25p | 14 | 28.57% | 2014-08-04 |
| NOI '09 - Pipe Marbles | noi09p5 | 17p | 33 | 10.61% | 2014-08-04 |
| NOI '09 - Tracing | noi09p6 | 50p | 0 | 0.00% | 2014-08-04 |
| NOI '10 - Energy Harvesting | noi10p1 | 17p | 25 | 28.26% | 2014-08-07 |
| NOI '10 - Super Piano | noi10p2 | 25p | 48 | 11.79% | 2014-08-07 |
| NOI '10 - Altitude | noi10p3 | 20p | 5 | 15.91% | 2014-08-07 |
| NOI '10 - Flight Control | noi10p4 | 20p | 10 | 17.19% | 2014-08-08 |
| NOI '10 - Route Planning | noi10p5 | 35p | 2 | 13.33% | 2014-08-08 |
| NOI '10 - Happily Growing | noi10p6 | 50p | 0 | - | 2014-08-08 |
| NOI '11 - Rabbit Farming | noi11p1 | 20p | 4 | 9.62% | 2014-08-10 |
| NOI '11 - Intelligent Car Racing | noi11p2 | 25p | 6 | 12.70% | 2014-08-10 |
| NOI '11 - Ali's Typewriter | noi11p3 | 30p | 21 | 32.58% | 2014-08-10 |
| NOI '11 - Road Construction | noi11p4 | 15p | 55 | 41.89% | 2014-08-10 |
| NOI '11 - NOI Carnival | noi11p5 | 25p | 11 | 14.29% | 2014-08-10 |
| NOI '11 - Bunny and Eggy's Game | noi11p6 | 25p | 5 | 12.00% | 2014-08-10 |
| NOI '12 - Random Number Generator | noi12p1 | 15p | 33 | 19.49% | 2014-08-13 |
| NOI '12 - Highway Cycling | noi12p2 | 25p | 10 | 13.91% | 2014-08-13 |
| NOI '12 - Magic Chessboard | noi12p3 | 40p | 6 | 3.73% | 2014-08-13 |
| NOI '12 - Lost in the Park | noi12p4 | 20p | 7 | 9.64% | 2014-08-13 |
| NOI '12 - Food Festival | noi12p5 | 30p | 4 | 11.67% | 2014-08-13 |
| NOI '12 - Triple Town | noi12p6 | 40p | 0 | 0.00% | 2014-08-19 |
| NOI '13 - Inner Product | noi13p1 | 20p | 8 | 5.56% | 2015-05-18 |
| NOI '13 - Tree Count | noi13p2 | 25p | 13 | 8.95% | 2015-05-18 |
| NOI '13 - Little Q's Training | noi13p3 | 25p | 0 | - | 2015-05-18 |
| NOI '13 - Matrix Game | noi13p4 | 20p | 15 | 21.92% | 2015-05-18 |
| NOI '13 - Calligrapher | noi13p5 | 30p | 2 | 26.32% | 2015-05-18 |
| NOI '13 - Fast Food Restaurant | noi13p6 | 30p | 4 | 15.56% | 2015-05-18 |
| NOI '14 - Getting-Up Syndrome | noi14p1 | 10p | 62 | 24.12% | 2015-05-19 |
| NOI '14 - Enchanted Forest | noi14p2 | 20p | 40 | 9.92% | 2015-05-19 |
| NOI '14 - Deletion Game | noi14p3 | 30p | 0 | 0.00% | 2015-05-19 |
| NOI '14 - Zoo | noi14p4 | 15p | 44 | 25.45% | 2015-05-20 |
| NOI '14 - Random Number Generator | noi14p5 | 20p | 24 | 13.18% | 2015-05-20 |
| NOI '14 - Ticket Purchase | noi14p6 | 30p | 15 | 8.14% | 2015-05-20 |
