1662. 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

Approach 1:

public class StringArrayEquivalent {
  public static void main(String[] args) {
    String[] word1 = {"ab", "c"};
    String[] word2 = {"a", "bc"};

    boolean answer = arrayStringsAreEqual(word1, word2);
    System.out.println("Both String arrays are equivalent: "+answer);
  }

  public static boolean arrayStringsAreEqual(String[] word1, String[] word2) 
  {
    StringBuilder sb1 = new StringBuilder();
    StringBuilder sb2 = new StringBuilder();

    for(String s:word1){
      sb1.append(s);
    }
    for(String s:word2){
      sb2.append(s);
    }
    if((sb1.toString().equals(sb2.toString()))){
      return true;
    }
    return false;
  }
}

output:

Both String arrays are equivalent: true

Step 1:

Initially, Create the new StringBuilder classes.

StringBuilder sb1 = new StringBuilder();

StringBuilder sb2 = new StringBuilder();

Step 2:

The string arrays can be converted to string.

convert the string array word1 into string by appending the each string to the StringBuilder class.

for(String s:word1){
    sb1.append(s);
}

Same for the word2 also.

Step 3:

Convert the StringBuilder to String using the toString() method.

We cannot directly compare the two StringBuilder objects because StringBuilder does not override the 'equals' method.

By default, the 'equals' method in 'Object' class compare the references, not their content.
To compare the content convert the StringBuilder to String using the toString() method.

step 4:

After converting to string check if both are equal return true else false.

My Solution Link: https://leetcode.com/problems/check-if-two-string-arrays-are-equivalent/submissions/1104840828/

Approach 2:

class Solution {
    public static void main(String[] args){
        String[] word1 = {"ab", "c"};
        String[] word2 = {"a", "bc"};

        boolean answer = arrayStringsAreEqual(word1, word2);
        System.out.println("Both String arrays are equivalent: "+answer);
    }
    public boolean arrayStringsAreEqual(String[] word1, String[] word2) {
        String s1 = String.join("",word1);
        String s2 = String.join("",word2);
        return s1.equals(s2);
    }
}