2060 - Check if an Original String Exists Given Two Encoded Strings\.

Hard

An original string, consisting of lowercase English letters, can be encoded by the following steps:

• Arbitrarily split it into a sequence of some number of non-empty substrings.

• Arbitrarily choose some elements (possibly none) of the sequence, and replace each with its length (as a numeric string).

• Concatenate the sequence as the encoded string.

For example, one way to encode an original string "abcdefghijklmnop" might be:

• Split it as a sequence: ["ab", "cdefghijklmn", "o", "p"].

• Choose the second and third elements to be replaced by their lengths, respectively. The sequence becomes ["ab", "12", "1", "p"].

• Concatenate the elements of the sequence to get the encoded string: "ab121p".

Given two encoded strings s1 and s2, consisting of lowercase English letters and digits 1-9 (inclusive), return true if there exists an original string that could be encoded as both s1 and s2. Otherwise, return false.

Note: The test cases are generated such that the number of consecutive digits in s1 and s2 does not exceed 3.

Example 1:

Input: s1 = "internationalization", s2 = "i18n"

Output: true

Explanation: It is possible that "internationalization" was the original string.

• "internationalization"

  -> Split: "internationalization"

  -> Do not replace any element

  -> Concatenate: "internationalization", which is s1.

• "internationalization"

  -> Split: "i", "nternationalizatio", "n"

  -> Replace: "i", "18", "n"

  -> Concatenate: "i18n", which is s2

Example 2:

Input: s1 = "l123e", s2 = "44"

Output: true

Explanation: It is possible that "leetcode" was the original string.

• "leetcode"

  -> Split: "l", "e", "et", "cod", "e"

  -> Replace: "l", "1", "2", "3", "e"

  -> Concatenate: "l123e", which is s1.

• "leetcode"

  -> Split: "leet", "code"

  -> Replace: "4", "4"

  -> Concatenate: "44", which is s2.

Example 3:

Input: s1 = "a5b", s2 = "c5b"

Output: false

Explanation: It is impossible.

• The original string encoded as s1 must start with the letter 'a'.

• The original string encoded as s2 must start with the letter 'c'.

Constraints:

• 1 <= s1.length, s2.length <= 40

• s1 and s2 consist of digits 1-9 (inclusive), and lowercase English letters only.

• The number of consecutive digits in s1 and s2 does not exceed 3.