Given strings s1, s2, and s3, find whether s3 is formed by an interleaving of s1 and s2.
An interleaving of two strings s and t is a configuration where they are divided into non-empty substrings such that:
s = s1 + s2 + ... + snt = t1 + t2 + ... + tm|n - m| <= 1s1 + t1 + s2 + t2 + s3 + t3 + ... or t1 + s1 + t2 + s2 + t3 + s3 + ...Note: a + b is the concatenation of strings a and b.
Example 1:
Input: s1 = "aabcc", s2 = "dbbca", s3 = "aadbbcbcac" Output: true
Example 2:
Input: s1 = "aabcc", s2 = "dbbca", s3 = "aadbbbaccc" Output: false
Example 3:
Input: s1 = "", s2 = "", s3 = "" Output: true
Constraints:
0 <= s1.length, s2.length <= 1000 <= s3.length <= 200s1, s2, and s3 consist of lowercase English letters.
Follow up: Could you solve it using only O(s2.length) additional memory space?