Coding Problems
Implement one function, run it against the worked examples, then submit it against the hidden cases. The same algorithms the tutorials walk through, with somewhere to actually type them.
Showing 1–15 of 15
| Title | Topics | Difficulty | |
|---|---|---|---|
1. Two Sum Find the two numbers in a sorted array that add up to a target. | arraystwo pointers | Easy | |
2. Count Vowels Count how many characters of a string are vowels. | strings | Easy | |
3. Move Zeroes Shift every zero to the end while keeping the other values in order. | arraystwo pointers | Easy | |
4. Count Set Bits For each number, count the 1 bits in its binary representation. | bit manipulation | Easy | |
5. Maximum Subarray Sum Find the largest sum obtainable from any contiguous run of values. | dynamic programmingarrays | Easy | |
6. Climbing Stairs Count the distinct ways to climb n steps taking one or two at a time. | dynamic programmingrecursion | Med. | |
7. Connected Components Group the nodes of an undirected graph into its connected components. | graphstraversal | Med. | |
8. Merge Intervals Collapse a list of intervals so no two of them overlap. | sortingintervals | Med. | |
9. Coin Change Find the fewest coins that add up to a target amount. | dynamic programming | Med. | |
10. Group Anagrams Cluster words that are rearrangements of each other. | hashingstrings | Med. | |
11. Course Schedule Decide whether a set of prerequisites can be satisfied at all. | graphstopological sort | Med. | |
12. Longest Increasing Subsequence Find the longest strictly increasing subsequence, which need not be contiguous. | dynamic programmingbinary search | Hard | |
13. Sliding Window Maximum Report the largest value in every window of fixed width as it slides. | arraysdeque | Hard | |
14. Edit Distance Count the fewest single-character edits that turn one word into another. | dynamic programmingstrings | Hard | |
15. Median of Two Sorted Arrays Find the median of two sorted arrays without merging them. | binary searcharrays | Exp. |