#584 · #721 · Accounts Merge(账户合并)

Given a list of accounts where accounts[i] = [name, email1, email2, ...], merge accounts that share any email. Two accounts belong to the same person if they share a common email. Return the merged accounts with emails sorted, in any order. Constraints: 1 <= accounts.length <= 1000, 1 <= emails per account <= 10.