Collapse Consecutive Duplicates

Medium ⏱ 12 min 61% acceptance ★★★★★ 4.6

Write collapse_consecutive(items) that returns a new list where every run of consecutive equal values is collapsed to a single value (unlike full dedup, non-adjacent repeats are kept separately).

Examples

Example 1

Input

items = [1, 1, 2, 2, 2, 1, 3, 3]

Output

[1, 2, 1, 3]

Explanation

Each run of identical neighbors collapses to one; the 1 reappears after the 2s since it is a new run.

Constraints

0 <= len(items) <= 10^5

Topics

ListsDeduplication

Companies

AmazonFlipkart

Hints

Hint 1

Walk through the list and only append a value if it differs from the last value appended.

← Maximum Sum of a Fixed-Size Window Weighted Average From a List of Tuples →

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