3163. String Compression III

Video description: https://youtu.be/92AmZ5xF7yI

Problem | Java Solution

Given a string word, compress it using the following algorithm:

Begin with an empty string comp. While word is not empty, use the follvowing operation:
Remove a maximum length prefix of word made of a single character c repeating at most 9 times.
Append the length of the prefix followed by c to comp.
Return the string comp.

Example 1:

Input: word = "abcde"

Output: "1a1b1c1d1e"

Explanation:

Initially, comp = "". Apply the operation 5 times, choosing "a", "b", "c", "d", and "e" as the prefix in each operation.

For each prefix, append "1" followed by the character to comp.

Example 2:

Input: word = "aaaaaaaaaaaaaabb"

Output: "9a5a2b"

Explanation:

Initially, comp = "". Apply the operation 3 times, choosing "aaaaaaaaa", "aaaaa", and "bb" as the prefix in each operation.

For prefix "aaaaaaaaa", append "9" followed by "a" to comp.
For prefix "aaaaa", append "5" followed by "a" to comp.
For prefix "bb", append "2" followed by "b" to comp.

Constraints:

1 <= word.length <= 2 * 105
word consists only of lowercase English letters.

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Solution

Figure out what all repetitions are for this letter, upon understanding this, take into consideration the limit of single character limit (in this case 9).

Now we have

• count and
• letter

Append this and append within the result string.

Here's the Java solution of it GitHub | Youtube