Remove Duplicate Characters, Keep Order

Medium ⏱ 12 min 46% acceptance ★★★★★ 4.7

Write remove_duplicates(s) that returns s with every repeated character removed, keeping only the first occurrence of each character and preserving the original order.

Examples

Example 1

Input

s = 'programming'

Output

'progamin'

Explanation

Repeated letters (the second r, second m, second g) are dropped; first occurrences are kept in order.

Example 2

Input

s = 'aabbcc'

Output

'abc'

Explanation

Only the first a, first b and first c survive.

Constraints

0 <= len(s) <= 10^4

Topics

StringsDeduplication

Companies

MetaLinkedIn

Hints

Hint 1

Track characters already seen in a set.

Hint 2

Append a character to the result only the first time you see it.

← Fill In Template Placeholders Strip Unwanted Characters from Input →

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