1662. Check If Two String Arrays are Equivalent

Problem

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 <= 10^3

• 1 <= word1[i].length, word2[i].length <= 10^3

• 1 <= sum(word1[i].length), sum(word2[i].length) <= 10^3

• word1[i] and word2[i] consist of lowercase letters.

Solution (Java)

class Solution {
    public boolean arrayStringsAreEqual(String[] word1, String[] word2) {
        StringBuilder sb1 = new StringBuilder();
        for (String word : word1) {
            sb1.append(word);
        }
        StringBuilder sb2 = new StringBuilder();
        for (String word : word2) {
            sb2.append(word);
        }
        return sb1.toString().equals(sb2.toString());
    }
}

Explain:

nope.

Complexity:

• Time complexity : O(n).
• Space complexity : O(n).