Coding Challenges
Practice. Prove. Get Hired. Solve real-world problems and showcase your skills to GCC employers.
243
Challenges
99
Easy
106
Medium
38
Hard
○
Serialize and Deserialize BST
Trees
String
Tree
DFS
3,328
Submissions
48.36%
Acceptance
○
Meeting Rooms II
Arrays
Array
Sorting
Heap
1,590
Submissions
55.71%
Acceptance
○
Maximal Square
Dynamic Programming
Array
Dynamic Programming
Matrix
5,674
Submissions
37.60%
Acceptance
○
Accounts Merge
Graphs
Array
String
DFS
13,081
Submissions
36.60%
Acceptance
○
Interval List Intersections
Arrays
Array
Two Pointers
12,694
Submissions
41.72%
Acceptance
○
Find All Anagrams in String
Strings
String
Sliding Window
Hash Table
2,166
Submissions
45.74%
Acceptance
○
Decode String
Strings
String
Stack
Recursion
10,222
Submissions
39.47%
Acceptance
○
Maximum Width of Binary Tree
Trees
Tree
BFS
DFS
6,448
Submissions
43.30%
Acceptance
○
All Paths From Source to Target
Graphs
Graph
Backtracking
BFS
11,840
Submissions
51.01%
Acceptance
○
Reorder List
Linked Lists
Linked List
Two Pointers
Stack
3,504
Submissions
58.15%
Acceptance
○
Gas Station
Arrays
Array
Greedy
14,401
Submissions
35.38%
Acceptance
○
Battleships in a Board
Arrays
Array
Matrix
DFS
9,752
Submissions
59.27%
Acceptance
○
Open the Lock
Graphs
Array
BFS
Hash Table
13,922
Submissions
56.67%
Acceptance
○
Asteroid Collision
Stacks
Array
Stack
2,741
Submissions
55.69%
Acceptance
○
Queue Reconstruction by Height
Arrays
Array
Greedy
Sorting
12,106
Submissions
57.72%
Acceptance
○
SQL: Select All Employees
SQL — Basics
SQL
SELECT
ORDER BY
598
Submissions
46.83%
Acceptance
○
SQL: Employee Count by Department
SQL — Aggregation
SQL
GROUP BY
COUNT
5,132
Submissions
36.35%
Acceptance
○
SQL: Second Highest Salary
SQL — Subqueries
SQL
Subquery
LIMIT
3,605
Submissions
43.78%
Acceptance
○
SQL: Duplicate Emails
SQL — Aggregation
SQL
GROUP BY
HAVING
12,760
Submissions
51.57%
Acceptance
○
SQL: Customers Never Ordered
SQL — Joins
SQL
LEFT JOIN
IS NULL
2,509
Submissions
43.04%
Acceptance