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AI writes a test for your language and level, checks your answers and tells you exactly what to study before your next coding interview.

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10 questions in your language

Big O, data structures and patterns, with real code in Python, Java, JavaScript or C++.

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Concrete next steps and classic problems to practice before your interview.

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Example question

What is the time complexity of has_pair?

A. O(n²)
B. O(n log n)
C. O(n) ✓
D. O(log n)

One pass over the list, and each set lookup and insert is O(1) on average. Every question in your test comes with an explanation like this.

question.py

1def has_pair(nums, target):
2    seen = set()
3    for x in nums:
4        if target - x in seen:
5            return True
6        seen.add(x)
7    return False