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Find Repeating Letters
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Find Repeating Letters

EasyPython

Problem

How would you write a program to find all repeating letters in a word?

Implement find_repeating_letters(word), returning each distinct letter that occurs at least twice, in the order of its first appearance. Matching is case-sensitive, and the input may contain Unicode characters.

Constraints

  • 0 <= len(word) <= 1000
  • The input is a Python string and may contain Unicode characters
  • Matching is case-sensitive
  • Return each repeated character once, ordered by first appearance

Function Signature

def find_repeating_letters(word):
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