Level 1Exercise #8

Deduplicate, keep order

Remove repeats while keeping each value's first occurrence. Target O(n) average time.

Sample Test Cases

Example #1

Input:dedupe([4, 2, 4, 1, 2, 3])

Output:[4,2,1,3]

Reference Solution

Reveal Reference Solution

def dedupe(values: list[int]) -> list[int]:
    seen, result = set(), []
    for value in values:
        if value not in seen:
            seen.add(value)
            result.append(value)
    return result

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Deduplicate, keep order

Sample Test Cases

Further Reading

Reference Solution