Apply Operations to Make String Empty
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array · hash table · sorting · counting
Description
You are given a string s.
Consider performing the following operation until s becomes empty:
- For every alphabet character from 'a' to 'z', remove the first occurrence of that character in s (if it exists).
For example, let initially s = "aabcbbca". We do the following operations:
- Remove the underlined characters s = "aabcbbca". The resulting string is s = "abbca".
- Remove the underlined characters s = "abbca". The resulting string is s = "ba".
- Remove the underlined characters s = "ba". The resulting string is s = "".
Return the value of the string s right before applying the last operation. In the example above, answer is "ba".
Example 1:
Example 2:
Solution