These are my solutions to codeforces.com problems. If you know of a better way to solve any of them, i'd love to hear from you! You can either create an issue or email me.
The problem statements can be found on https://codeforces.com/problemset/problem/<directory>/<filenameWithoutExtension>. For example, the problem for 96/a can be found at https://codeforces.com/problemset/problem/96/a.
Based on the problems i've attempted so far:
| Difficulty | What is needed to solve this (on top of skills from lower difficulty) |
|---|---|
| 800 | conditionals |
| 900 | loops |
| 1000 | math, simple puzzle |
| 1100 | math, simple puzzle |
| 1200 | sorting, multi-dimensional arrays, 1d constructive algorithm |
| 1300 | sorting, 2d constructive algorithm, divisibility |
| 1400 | 2d transformations, bitmask, heap, large numbers |
| 1500 | repeated operations between 2 x 1d-arrays, memoization |
| 1600 | hard-coded maps, tree traversal with info tracking, combinatorics (n^2 -> n) |
| 1800 | dynamic programming |
| 1900 | combinatorics (n^4 -> n^2) |
Let me know if you encounter a problem which doesn't match up to my table above.