Trace n = 6, connections = [[0,1],[0,2],[0,3],[1,2],[1,3]].
cables, need minimum for computers. We have exactly enough.
Union operations: union(0,1), union(0,2), union(0,3), union(1,2) [already same], union(1,3) [already same].
After processing: {0,1,2,3} form one component. {4} alone. {5} alone.
Components: .
Operations needed: . Move redundant cables to connect computers 4 and 5.
time for edges. space.