Check If Two String Arrays are Equivalent

class Solution {
public:
    bool compareStringArrays(vector<string>& arr1, vector<string>& arr2) {
        string concatenatedSecond = accumulate(arr2.begin(), arr2.end(), string());
        int pos = 0;
        for (const auto& part : arr1) {
            for (char ch : part) {
                if (pos >= concatenatedSecond.length() || ch != concatenatedSecond[pos]) {
                    return false;
                }
                pos++;
            }
        }
        return pos == concatenatedSecond.length();
    }
};

The solution provided in C++ addresses the problem of determining if two arrays of strings are equivalent when concatenated into a single string. Follow this approach to understand and implement the solution:

• Start by concatenating all the strings in the second array (arr2) into one single string named concatenatedSecond. This is done efficiently using the accumulate function from the Standard Library.

• Initialize a position tracker pos to zero. This variable will help track the position in the concatenated string of arr2.

• Iterate through each string in the first array (arr1). For each string, further iterate through each character.

  • For each character in the string from arr1, compare it with the character at the current position in concatenatedSecond. If they don't match or if pos exceeds the length of concatenatedSecond, return false.

  • If they match, increment the pos to continue the comparison with the next character.

• After all characters in all strings of arr1 have been successfully compared, check if pos equals the length of concatenatedSecond. This is to ensure that all characters in both concatenated strings have been compared and are equivalent.

• If the final comparison of lengths is true, return true indicating that when concatenated, both string arrays produce an equivalent string. Otherwise, return false.

This approach ensures that the solution is efficient by directly comparing strings without the need for concatenating the first array. It handles various edge cases such as different array lengths and differing string lengths within the arrays.

class Solution {
    public boolean checkEqualStringArrays(String[] firstArray, String[] secondArray) {
        String secondConcat = String.join("", secondArray);
        int currentIndex = 0;
        for (String piece : firstArray) {
            for (char character : piece.toCharArray()) {
                if (currentIndex >= secondConcat.length() || character != secondConcat.charAt(currentIndex)) {
                    return false;
                }
                currentIndex++;
            }
        }
        return currentIndex == secondConcat.length();
    }
}

Given the problem "Check If Two String Arrays are Equivalent", the solution involves checking whether the concatenation of strings from two arrays results in identical strings. The implementation is in Java.

Follow these steps outline the core logic:

1. Use String.join("", secondArray) to concatenate all strings in the secondArray into a single string named secondConcat.
2. Initialize currentIndex to 0, which will track the character position in secondConcat.
3. Iterate over each string in the firstArray.
   • For each string, iterate over its characters.
   • Check if currentIndex has not exceeded the length of secondConcat and if the current character matches the corresponding character in secondConcat.
   • If the conditions are not met, return false.
   • Increment currentIndex after comparing each character.
4. After exiting the loops, check if currentIndex equals the length of secondConcat to ensure complete and exact matching without leftover characters.

If the loops complete without returning false, and the final position index matches the length of the concatenated string in secondArray, the function returns true, indicating the arrays are equivalent. Otherwise, if any mismatch occurs or if the lengths are unequal, false is returned.

class Solution:
    def arraysEqual(self, arr1: List[str], arr2: List[str]) -> bool:
        concatenated_arr2 = ''.join(arr2)
        cur_index = 0
        for sub_str in arr1:
            for char in sub_str:
                if cur_index >= len(concatenated_arr2) or char != concatenated_arr2[cur_index]:
                    return False
                cur_index += 1
        return cur_index == len(concatenated_arr2)

This Python solution addresses the problem of determining whether two arrays of strings are equivalent when concatenated into a single string. The method defined within the Solution class checks this equivalence effectively by:

• First concatenating all strings in the second array (arr2) into a single string concatenated_arr2.
• The function then iterates over each substring in the first array (arr1), and subsequently over each character in these substrings.
• It uses a tracking index, cur_index, to align the current character in arr1 with its counterpart in the concatenated string from arr2.
• If cur_index surpasses the length of concatenated_arr2 or a character mismatch occurs, the function immediately returns False, indicating the arrays are not equivalent.
• After completing the iterations, the method returns True if the ending cur_index matches the length of concatenated_arr2.

By leveraging this approach, ensure reliable and straightforward validation of equivalent concatenated outcomes for two string arrays.