A chat app wants to show how many separate groups its users form. Users are numbered 0 to n - 1, and pairs[i] = [a, b] means a and b have chatted. Two users are in the same group if you can get from one to the other through a chain of chats.
Write countGroups(n, pairs) that returns the number of separate groups. A user who has never chatted is a group of one.
Input: n = 5, pairs = [[0,1],[1,2],[3,4]] Output: 2
Users 0, 1, and 2 form one group; 3 and 4 form another.
Input: n = 3, pairs = [] Output: 3
Nobody has chatted, so each user is alone.
1 <= n <= 100000 <= pairs.length <= 500000 <= a, b < nRun tries your code on the examples. Submit runs every test, including hidden edge cases, and solves the problem when they all pass.
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I'm here to help with #415 Count Separate Chat Groups. I give hints, never the solution, so you get to solve it yourself. Ask for a hint, select code to ask about it, or press Ask Tuto why on a failing test.
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