Question 1

Is CodexSheet free?

Accepted Answer

The Algorithm Labs - 22 animated, step-by-step simulations of sorting, two pointers, sliding window, prefix sums, binary search, stacks, queues, linked lists, hashing, trees, graphs, union-find, dynamic programming, recursion, backtracking and greedy - are free with no sign-in, as is the mentorship page. The full workspace unlocks with one Family Pass.

Question 2

What makes CodexSheet different from a list of LeetCode links?

Accepted Answer

Every algorithm on CodexSheet runs for real on the numbers you type. Paste your own array, graph or knapsack table and the simulation steps through the actual execution with the comparison, write and probe counts, so you learn the invariant instead of memorising the code.

Question 3

Does the code editor actually run my solution?

Accepted Answer

Yes. Python, Java, C++ and JavaScript submissions are compiled and executed against hidden test cases with real verdicts, runtime and memory - not a syntax check.