Level 1Exercise #24

Sparse vector dot product

Return the dot product of two sparse vectors stored as index:value dictionaries.

Sample Test Cases

Example #1

Input:sparse_dot({0: 4, 3: 2}, {1: 5, 3: 7})

Output:14

Reference Solution

Reveal Reference Solution

def sparse_dot(a: dict[int, int], b: dict[int, int]) -> int:
    if len(a) > len(b):
        a, b = b, a
    return sum(value * b.get(index, 0) for index, value in a.items())

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Sparse vector dot product

Sample Test Cases

Further Reading

Reference Solution