Number of Operations to Make Network Connected
There are n computers numbered from 0 to n - 1 connected by ethernet cables connections, where connections[i] = [ai, bi] represents a connection between computers ai and bi. Any computer can reach any other computer directly or indirectly through the network.
You are given an initial computer network connections. You can extract certain cables between two directly connected computers, and place them between any pair of disconnected computers to make them directly connected.
Return the minimum number of times you need to do this in order to make all the computers connected. If it is not possible, return -1.
Example 1
Input
n = 4, connections = [[0,1],[0,2],[1,2]]Output
1Remove the cable between computers 1 and 2 and place it between computers 1 and 3.
Example 2
Input
n = 6, connections = [[0,1],[0,2],[0,3],[1,2],[1,3]]Output
2Two cable moves are needed to connect all six computers.
Constraints
- 1 <= n <= 10^5
- 1 <= connections.length <= min(n * (n - 1) / 2, 10^5)
- connections[i].length == 2
- 0 <= ai, bi < n
- ai != bi
- There are no repeated connections.
- No two computers are connected by more than one cable.
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