CheckIf2StringsAreEquivalent.py

'''
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.
'''

class Solution:
    def arrayStringsAreEqual(self, word1: List[str], word2: List[str]) -> bool:
        w1 = w2 = 0 #index of word

        i = j = 0  # index of char in word

        while w1 < len(word1) and w2 < len(word2):
            if word1[w1][i] != word2[w2][j]:
              return False

            i, j = i+1, j+1
            if i == len(word1[w1]):
                w1 += 1
                i = 0
            
            if j == len(word2[w2]):
                w2 += 1
                j = 0

        if w1 != len(word1) or w2!= len(word2):
          return False
        else:
          return True

'''
Runtime 37 ms Beats 77.73%
Memory 16.5 MB Beats 13.49%
'''