CodeSignal Technical Assessment Coding Fundamentals 3

Question 1

Which data structure is most efficient for implementing a priority queue?

Accepted Answer

Binary Heap

Answer

A binary heap supports O(log n) insertion and O(log n) extraction of the minimum/maximum, making it ideal for priority queues.

Question 2

What is the output of the following Python code?
```
def f(x, lst=[]):
    lst.append(x)
    return lst
print(f(1))
print(f(2))
```

Accepted Answer

[1]
[1, 2]

Answer

Python default mutable arguments are shared across calls, so the same list persists between invocations.

Question 3

In Big-O notation, which represents the fastest growth rate?

Accepted Answer

O(2ⁿ)

Answer

Exponential time O(2ⁿ) grows faster than polynomial complexities like O(n²) or O(n³) for large n.

Question 4

What is a key difference between a shallow copy and a deep copy of an object?

Accepted Answer

Deep copy duplicates nested objects; shallow copy only copies top-level references

Answer

A shallow copy copies the container but not nested objects, which are still shared; a deep copy recursively copies everything.

Question 5

Which statement about recursion is TRUE?

Accepted Answer

Every recursive function must have a base case to avoid infinite recursion

Answer

A base case is required in recursion to stop the recursive calls; without it, the function calls itself indefinitely.

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