check-if-two-string-arrays-are-equivalent.md

Code

func arrayStringsAreEqual(word1 []string, word2 []string) bool {
	i1 := 0
	i2 := 0
	j1 := 0
	j2 := 0
	n1 := len(word1)
	n2 := len(word2)
	w1 := len(word1[0])
	w2 := len(word2[0])

	for i1 < n1 && i2 < n2 {
		if word1[i1][j1] != word2[i2][j2] {
			return false
		} else {
			j1 += 1
			j2 += 1

			if j1 == w1 {
				j1 = 0
				i1 += 1
			}

			if j2 == w2 {
				j2 = 0
				i2 += 1
			}

			if i1 == n1 || i2 == n2 {
				break
			}

			w1 = len(word1[i1])
			w2 = len(word2[i2])
		}
	}

	if i1 == n1 && i2 == n2 {
		return true
	}

	return false
}

Solution in mind

• We make use of 4 indices, i1, i2, j1, j2, where i corresponds to the ith word of given subscript and the respective j are indices of the letter in that word.

• We initialise all the above variables to 0. We begin a while loop where we continue to iterate through the words till we reach the last in either word1 or word2.

• In the loop, we check if the letter word1[i1][j1] == word2[i2][j2]. If not, we can immediately conclude that the strings do not match and we can return false.

• If they do match, we have to check the next letter. This letter can either be part of the same word or the first letter in the next word.

• We thus first increment the j indices and check if it has reached the end of the word (last character). If yes, we reset j to 0 and increment the respective i value so as to move to the next word in the list.

• If either i exceeds the last index in corresponding word, we break from the while loop. Upon exiting the loop, we can conclude if both words match if i1 == n1 && i2 == n2. This condition holds if and only if, all words have been matched from both lists.