Leetcode 544. Output Contest Matches

Given n (a power of two) teams labeled 1..n, build the full tournament bracket string by repeatedly pairing outermost teams (1 with n, 2 with n-1, etc.) and combining matched pairs into parenthesized strings until one string remains. This is a divide-and-conquer/string-concatenation problem that can be solved iteratively or recursively by merging pairs each round.