Syncing your progress...
Stop memorising problems.
Start seeing patterns.
Most interview questions are a handful of patterns in disguise. Learn to spot them - practised on real problems, with every line of your code visible as it runs.
Guided roadmapsFree to start
How it works
1
Pick a problem
Curated DSA challenges, ranked by difficulty.
2
Write & run code
Python or Java, checked against real test cases.
3
Visualize execution
Step through your code and watch memory change live.
Visualizer previewTry it
def two_sum(nums, target):
seen = {}
for i, n in enumerate(nums):
need = target - n
if need in seen:
return [seen[need], i]
seen[n] = i
Array — nums
2
7
11
15
i = 1
Dict — seen
{ 2: 0 }
Command line
Download →$ codemeal problem solve 42
📝 Solution file created
~/.codemeal/solutions/42/solution.py
$ codemeal problem submit 42
✅ Example 1 passed
✅ Example 2 passed
🎉 Solution accepted! Passed: 12/12
Solve from your terminal
Pull a problem down, solve it in your own editor, and submit — your progress syncs straight back here.
- Your editor, your keybindings
- Runs tests before you submit
- macOS, Linux & Windows
YouTube
Visit channel →Arrays — தமிழில்14:02
Watch it explained in Tamil
Handy when the written version isn't landing — the same ideas, talked through from the start.
- Explained out loud, in Tamil
- Same topics as the tutorials here
- Free, no account needed