A2OJ Ladders
This ladder provides a structured path for users with a Codeforces Rating between 1900 to 1999. It has different levels of difficulty, helping them to systematically improve their problem-solving skills. A2OJ ladders have proven to be beneficial for many competitive programmers over the years.
Also known as ACD Ladder 1900–1999, A2OJ Ladder.
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0/100
Overall progress
0 / 100
0/14
Easy
0/15
Medium
0/71
Hard
| Status | Problem | Solve | Practice | Revision | Level | |
|---|---|---|---|---|---|---|
| 1. | Sereja and Dima |  | Easy | |||
| 2. | Gravity Flip | | Easy | |||
| 3. | Little Pony and Crystal Mine | | Easy | |||
| 4. | Anton and Letters | | Easy | |||
| 5. | Fox And Snake | | Easy | |||
| 6. | inc ARG | | Easy | |||
| 7. | Caisa and Pylons | | Easy | |||
| 8. | Puzzles | | Easy | |||
| 9. | Chat room | | Easy | |||
| 10. | Vasya and Socks | | Easy | |||
| 11. | I Wanna Be the Guy | | Easy | |||
| 12. | Expression | | Easy | |||
| 13. | Counterexample | | Easy | |||
| 14. | Flipping Game | | Medium | |||
| 15. | Pashmak and Garden | | Medium | |||
| 16. | Ilya and Queries | | Easy | |||
| 17. | Cheap Travel | | Medium | |||
| 18. | Little Pony and Expected Maximum | | Medium | |||
| 19. | Caisa and Sugar | | Medium | |||
| 20. | Cut Ribbon | | Medium | |||
| 21. | Writing Code | | Hard | |||
| 22. | Tennis Game | | Hard | |||
| 23. | Towers | | Medium | |||
| 24. | Ryouko's Memory Note | | Hard | |||
| 25. | Knight Tournament | | Medium | |||
| 26. | Andrey and Problem | | Hard | |||
| 27. | Password | | Medium | |||
| 28. | Interesting Array | | Hard | |||
| 29. | Fox And Two Dots | | Medium | |||
| 30. | Xenia and Bit Operations | | Medium | |||
| 31. | k-Tree | | Medium | |||
| 32. | Read Time | | Hard | |||
| 33. | Boredom | | Medium | |||
| 34. | Fools and Roads | | Hard | |||
| 35. | DZY Loves Sequences | | Medium | |||
| 36. | Breaking Good | | Hard | |||
| 37. | Red-Green Towers | | Hard | |||
| 38. | Pashmak and Buses | | Hard | |||
| 39. | Mashmokh and Reverse Operation | | Hard | |||
| 40. | Sereja and Table | | Hard | |||
| 41. | R2D2 and Droid Army | | Hard | |||
| 42. | Strip | | Hard | |||
| 43. | Destroying Roads | | Hard | |||
| 44. | A and B and Lecture Rooms | | Hard | |||
| 45. | Obsessive String | | Hard | |||
| 46. | Restore Cube | | Hard | |||
| 47. | Roman and Numbers | | Hard | |||
| 48. | Water Tree | | Hard | |||
| 49. | Towers | | Hard | |||
| 50. | Maximum Value | | Hard | |||
| 51. | Valera and Swaps | | Hard | |||
| 52. | Increase Sequence | | Hard | |||
| 53. | Wonder Room | | Hard | |||
| 54. | Devu and Partitioning of the Array | | Medium | |||
| 55. | Gerald and Giant Chess | | Hard | |||
| 56. | Watching Fireworks is Fun | | Hard | |||
| 57. | Jeff and Rounding | | Hard | |||
| 58. | Ciel the Commander | | Hard | |||
| 59. | Painting Fence | | Hard | |||
| 60. | Little Pony and Harmony Chest | | Hard | |||
| 61. | Case of Chocolate | | Hard | |||
| 62. | Lucky Common Subsequence | | Hard | |||
| 63. | Sereja and Brackets | | Hard | |||
| 64. | Kalila and Dimna in the Logging Industry | | Hard | |||
| 65. | String | | Hard | |||
| 66. | Civilization | | Hard | |||
| 67. | XOR on Segment | | Hard | |||
| 68. | Prefixes and Suffixes | | Hard | |||
| 69. | Appleman and Tree | | Hard | |||
| 70. | Enemy is weak | | Hard | |||
| 71. | Jzzhu and Cities | | Hard | |||
| 72. | Substitutes in Number | | Hard | |||
| 73. | Little Elephant and Array | | Hard | |||
| 74. | Pashmak and Graph | | Hard | |||
| 75. | Propagating tree | | Hard | |||
| 76. | Match & Catch | | Hard | |||
| 77. | A Simple Task | | Hard | |||
| 78. | Prefix Product Sequence | | Hard | |||
| 79. | Vasya and Beautiful Arrays | | Hard | |||
| 80. | Road Improvement | | Hard | |||
| 81. | Tree Requests | | Hard | |||
| 82. | Sereja and Squares | | Hard | |||
| 83. | LIS of Sequence | | Hard | |||
| 84. | Jzzhu and Numbers | | Hard | |||
| 85. | Captains Mode | | Hard | |||
| 86. | Mike and Foam | | Hard | |||
| 87. | Devu and Birthday Celebration | | Hard | |||
| 88. | Martian Strings | | Hard | |||
| 89. | Hill Climbing | | Hard | |||
| 90. | Antimatter | | Hard | |||
| 91. | Tricky Function | | Hard | |||
| 92. | The Child and Sequence | | Hard | |||
| 93. | Tanya and Password | | Hard | |||
| 94. | Fedor and Essay | | Hard | |||
| 95. | Xenia and Tree | | Hard | |||
| 96. | DZY Loves Fibonacci Numbers | | Hard | |||
| 97. | Ann and Half-Palindrome | | Hard | |||
| 98. | Kindergarten | | Hard | |||
| 99. | Tree and Queries | | Hard | |||
| 100. | Serega and Fun | | Hard |
There is no PDF here, and you do not need one. All 100 problems are listed in full on this page, free and without an account — and unlike a PDF the list remembers what you have ticked off, so you are not re-reading a static file to work out where you stopped. Use your browser's print view if you want it on paper.
Yes — same sheet, different name. It is also known as ACD Ladder 1900–1999, A2OJ Ladder. Whichever name you searched for, this is the tracker for it.
Tick a problem on this page and it stays ticked. Progress saves in your browser straight away with no account, and the counts update per section so you can see which parts of 1900-1999 A2OJ: Ladder you have actually covered. Signing in with Google syncs it across devices.
At roughly 25 minutes a problem — reading it, solving it and writing the approach down — 100 problems is about 42 hours, or 4 weeks at ten hours a week. Treat that as a planning figure rather than a promise; the first pass through an unfamiliar topic is always slower.
Yes, completely, and no account is needed. There is no paid tier and nothing is held back — the sheet itself is by A2OJ Ladders, and this is a free tracker for it.
Finish one. Sheets overlap heavily, so working several in parallel mostly means re-solving the same problems while never completing a full topic sweep. If you are not sure this is the right one for the time you have, the sheet comparison page puts the options side by side with hour estimates.