Check If Two String Arrays are Equivalent

Given two string arrays word1 and word2, return true if the two arrays represent the same string, and false otherwise.

A string is represented by an array if the array elements concatenated in order forms the string.

Example 1:

Input: word1 = ["ab", "c"], word2 = ["a", "bc"]
Output: true
Explanation:
word1 represents string "ab" + "c" -> "abc"
word2 represents string "a" + "bc" -> "abc"
The strings are the same, so return true.

Example 2:

Input: word1 = ["a", "cb"], word2 = ["ab", "c"]
Output: false

Example 3:

Input: word1 = ["abc", "d", "defg"], word2 = ["abcddefg"]
Output: true

Constraints:

• 1 <= word1.length, word2.length <= 103
• 1 <= word1[i].length, word2[i].length <= 103
• 1 <= sum(word1[i].length), sum(word2[i].length) <= 103
• word1[i] and word2[i] consist of lowercase letters.

SOLUTION:

class Solution:
    def arrayStringsAreEqual(self, word1: List[str], word2: List[str]) -> bool:
        m = len(word1)
        n = len(word2)
        a, b = 0, 0
        c, d = 0, 0
        while a < m and c < n:
            if word1[a][b] != word2[c][d]:
                return False
            a, b = a + (b + 1) // len(word1[a]), (b + 1) % len(word1[a])
            c, d = c + (d + 1) // len(word2[c]), (d + 1) % len(word2[c])
        return a >= m and c >= n