3597. Partition String

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Given a string s, partition it into unique segments according to the following procedure:

  • Start building a segment beginning at index 0.
  • Continue extending the current segment character by character until the current segment has not been seen before.
  • Once the segment is unique, add it to your list of segments, mark it as seen, and begin a new segment from the next index.
  • Repeat until you reach the end of s.

Return an array of strings segments, where segments[i] is the ith segment created.

 

Example 1:

Input: s = "abbccccd"

Output: ["a","b","bc","c","cc","d"]

Explanation:

Index Segment After Adding Seen Segments Current Segment Seen Before? New Segment Updated Seen Segments
0 "a" [] No "" ["a"]
1 "b" ["a"] No "" ["a", "b"]
2 "b" ["a", "b"] Yes "b" ["a", "b"]
3 "bc" ["a", "b"] No "" ["a", "b", "bc"]
4 "c" ["a", "b", "bc"] No "" ["a", "b", "bc", "c"]
5 "c" ["a", "b", "bc", "c"] Yes "c" ["a", "b", "bc", "c"]
6 "cc" ["a", "b", "bc", "c"] No "" ["a", "b", "bc", "c", "cc"]
7 "d" ["a", "b", "bc", "c", "cc"] No "" ["a", "b", "bc", "c", "cc", "d"]

Hence, the final output is ["a", "b", "bc", "c", "cc", "d"].

Example 2:

Input: s = "aaaa"

Output: ["a","aa"]

Explanation:

Index Segment After Adding Seen Segments Current Segment Seen Before? New Segment Updated Seen Segments
0 "a" [] No "" ["a"]
1 "a" ["a"] Yes "a" ["a"]
2 "aa" ["a"] No "" ["a", "aa"]
3 "a" ["a", "aa"] Yes "a" ["a", "aa"]

Hence, the final output is ["a", "aa"].

 

Constraints:

  • 1 <= s.length <= 105
  • s contains only lowercase English letters.

Hints

Hint 1
Simulate as described