99 Problems
Solutions to 99 Problems implemented in Reason.
Status
Currently in progress.
Working with lists
| No. | Description | Solution | No. | Description | Solution | |
|---|---|---|---|---|---|---|
| 01 | Last element | completed | 15 | Replicate | completed | |
| 02 | Last two elements | completed | 16 | Drop every N'th | completed | |
| 03 | K'th element | completed | 17 | Split | completed | |
| 04 | Length | completed | 18 | Slice | completed | |
| 05 | Reverse | completed | 19 | Rotate | completed | |
| 06 | Palindrome | completed | 20 | Remove | completed | |
| 07 | Flatten | completed | 21 | Insert | completed | |
| 08 | Eliminate duplicates | completed | 22 | Range | completed | |
| 09 | Pack duplicates | completed | 23 | Random select | completed | |
| 10 | Run-length | completed | 24 | Random numbers | completed | |
| 11 | Modified run-length | completed | 25 | Random permutation | completed | |
| 12 | Decode run-length | completed | 26 | Combinations | completed | |
| 13 | Direct run-length | completed | 27 | Group | completed | |
| 14 | Duplicate | completed | 28 | Sort by length | completed |
Arithmetic
| No. | Description | Solution | No. | Description | Solution | |
|---|---|---|---|---|---|---|
| 31 | Prime | completed | 37 | Improve 32 | completed | |
| 32 | GCD | completed | 38 | Compare 32 and 35 | completed | |
| 33 | Coprime | completed | 39 | List prime numbers | completed | |
| 34 | Euler's totient | completed | 40 | Goldbach's conjecture | completed | |
| 35 | Prime factors | completed | 41 | Goldbach compositions | completed | |
| 36 | Prime factors (pair) | completed |
Logic and Codes
| No. | Description | Solution |
|---|---|---|
| 46 | Truth tables for logical expressions | completed |
| 47 | Truth tables for logical expressions (2) | completed (combined with 46) |
| 48 | Truth tables for logical expressions (3) | completed |
| 49 | Gray code | completed |
| 50 | Huffman code | completed |
Binary Trees
| No. | Description | Solution | No. | Description | Solution | |
|---|---|---|---|---|---|---|
| 54A | Check Binary Tree | No need as type checked | 62 | Collect internals | completed | |
| 55 | Completely balanced | completed | 62B | Collect nodes at a level | completed | |
| 56 | Symmetric | completed | 63 | Complete binary tree | completed | |
| 57 | Binary search trees | completed | 64 | Layout 1 | completed | |
| 58 | Generate-and-test | completed | 65 | Layout 2 | completed | |
| 59 | Height-balanced | completed | 66 | Layout 3 | completed | |
| 60 | 48 with N nodes | completed | 67A | Stringify | completed | |
| 61 | Count leaves | completed | 68 | Preorder and inorder | completed | |
| 61A | Collect leaves | completed | 69 | Dotstring | completed |
Multiway Trees
| No. | Description | Solution |
|---|---|---|
| 70B | Check Multiway Tree | No need as type checked |
| 70C | Count nodes | completed |
| 70 | Node string | completed |
| 71 | Internal path length | completed |
| 72 | Bottom-up order | completed |
| 73 | Lisp-like tree | completed |
Graphs
| No. | Description | Solution | No. | Description | Solution | |
|---|---|---|---|---|---|---|
| 80 | Conversions | completed | 85 | Graph isomorphism | completed | |
| 81 | Path | completed | 86 | Graph coloration | completed | |
| 82 | Cycle | completed | 87 | Depth-first traversal | completed | |
| 83 | Spanning trees | completed | 88 | Connected components | completed | |
| 84 | Minimal spanning tree | completed | 89 | Bipartite graphs | Not implemented |
Miscellaneous Problems
| No. | Description | Solution | No. | Description | Solution | |
|---|---|---|---|---|---|---|
| 90 | Eight queens problem | completed | 95 | English number words | completed | |
| 91 | Knight's tour | completed | 96 | Syntax checker | completed | |
| 92 | Von Koch's conjecture | completed | 97 | Sudoku | completed | |
| 93 | An arithmetic puzzle | completed | 98 | Nonograms | completed | |
| 94 | K-regular simple graphs | completed | 99 | Crossword puzzle | Not implemented |