Remove Duplicates

Problem Statement

Given a s S, your task is to remove all duplicate characters from the s S.

NOTE:

1. The order of characters in the output s should be the same as given in the input s.
2. String S contains only lowercase characters [‘a’-‘z’].

Input Format:

• The input contains a single s S.

Output Format:

• Print the s S with no duplicate characters.

Constraints:

• Test Files 1 to 5: 10 <= length of S <= 15
• Test Files 6 to 10: 1 <= length of S <= 100000

Solution

s = input()
seen = set()
result = ''
for c in s:
    if c not in seen:
        seen.add(c)
        result += c
return result