Smallest Subsequence of Distinct Characters
Given a string s, return the lexicographically smallest subsequence of s that contains all the distinct characters of s exactly once.
Note: This question is the same as 316: https://leetcode.com/problems/remove-duplicate-letters/
Example 1
Input
s = "bcabc"Output
"abc"The lexicographically smallest subsequence containing each distinct character in
s exactly once is "abc".Example 2
Input
s = "cbacdcbc"Output
"acdb"The lexicographically smallest subsequence containing each distinct character in
s exactly once is "acdb".Constraints
- 1 <= s.length <= 1000
- s consists of lowercase English letters.