1081. Smallest Subsequence of Distinct Characters
String
Stack
Greedy
Monotonic Stack
Given a string s, return the lexicographically smallest subsequence of s that contains all the distinct characters of s exactly once.
Examples
Example 1
Input: s = "bcabc"
Output: "abc"
Example 2
Input: s = "cbacdcbc"
Output: "acdb"
Constraints
1 <= s.length <= 1000s consists of lowercase English letters.