Count Similar Photo Groups

You are given `n` photos labeled `0` to `n - 1` and an `n x n` binary matrix `isSimilar`. - `isSimilar[i][j] = 1` means photo `i` and photo `j` are **directly similar**. - `isSimilar[i][j] = 0` means they are not directly similar. Similarity is also **transitive**: if photo `A` is similar to `B`, and `B` is similar to `C`, then `A` is considered similar to `C` even if `A` and `C` are not directly similar. Treat each set of directly or indirectly similar photos as one **photo group**. Return the total number of photo groups. You may assume the similarity relationship is symmetric, so if `isSimilar[i][j] = 1`, then `isSimilar[j][i] = 1`.