2746. Decremental String Concatenation

You are given a 0-indexed array words containing n strings. Let's define a join operation join(x, y) between two strings x and y as concatenating them into xy. However, if the last character of x is equal to the first character of y, one of them is deleted. For example join("ab", "ba") = "aba" and join("ab", "cde") = "abcde". You are to perform n - 1 join operations. Let str0 = words[0]. Starti