Code RoomMinimum spanning tree
MediumPrep Room Coding #851

Minimum spanning tree

CodingAlgorithms & data structuresMid–Senior~25 min

Given n nodes labeled 0..n-1 and a list of weighted undirected edges [u, v, w], return the total weight of a minimum spanning tree. When several edges have equal weight the choice does not affect total weight, but break ties deterministically by (weight, u, v). If the graph is disconnected and no spanning tree exists, return -1. A single node with no edges has MST weight 0.

Implement
mst_weight(n: int, edges: list[list[int]]) → int
Examples
in[4,[[0,1,1],[1,2,2],[2,3,3],[0,3,4]]]out6
What a strong answer looks like

State your approach and its time/space complexity out loud before you optimize. Handle the edge cases (empty input, duplicates, overflow), and say why you chose this over the brute force. Green tests are the floor, not the grade.

0:00 of about 25 min
InputExpectedGot
[4,[[0,1,1],[1,2,2],[2,3,3],[0,3,4]]]6not run yetsample