LeetCode 1319 Number of Operations to Make Network Connected - Problem Statement

Given n computers and a list of cable connections, return the minimum number of cable moves to connect all computers.

You can disconnect a cable between two connected computers and reconnect it elsewhere.

With n = 4 and connections = [[0,1],[0,2],[1,2]]:

• Computers 0, 1, 2 are connected. Computer 3 is isolated.
• The 0-1-2 triangle has an extra cable (only need $2$ cables for $3$ computers).
• Move the redundant cable to connect computer 3.
• Answer: $1$ operation.

Return $-1$ if impossible (not enough cables).

Constraints: $1 \le n \le 10^5$.