Practice
Problems to sharpen your skills before a test or an interview. Try as often as you like: nothing here is seen by employers.
Solved 0 of 62
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| Problem | Area | Kind | Difficulty | Your progress |
|---|---|---|---|---|
| Two sum | Arrays | Code | easy | Not tried |
| Largest sum of a run | Arrays | Code | medium | Not tried |
| Turn a grid | Arrays | Code | medium | Not tried |
| Add two numbers | Basics | Code | easy | Not tried |
| FizzBuzz | Basics | Code | easy | Not tried |
| Totals per team | Data | Code | medium | Not tried |
| Least recently used cache | Design | Code | hard | Not tried |
| Compare versions | DevOps | Code | easy | Not tried |
| Count errors in a log | DevOps | Code | easy | Not tried |
| Climbing stairs | Dynamic programming | Code | easy | Not tried |
| Fewest coins | Dynamic programming | Code | medium | Not tried |
| Count the islands | Graphs | Code | medium | Not tried |
| Shortest way out | Graphs | Code | medium | Not tried |
| First letter that appears once | Hash maps | Code | easy | Not tried |
| Most common word | Hash maps | Code | easy | Not tried |
| The k most frequent numbers | Heaps | Code | medium | Not tried |
| Find the position | Searching and sorting | Code | easy | Not tried |
| Merge meeting times | Searching and sorting | Code | medium | Not tried |
| Balanced brackets | Stacks and queues | Code | easy | Not tried |
| Palindrome check | Strings | Code | easy | Not tried |
| Reverse the words | Strings | Code | easy | Not tried |
| Roman numerals | Strings | Code | easy | Not tried |
| Valid anagram | Strings | Code | easy | Not tried |