MST - Minimum Spanning Tree
Find the minimum spanning tree of the graph.
On the first line there will be two integers N - the number of nodes and M - the number of edges. (1 <= N <= 10000), (1 <= M <= 100000)
M lines follow with three integers i j k on each line representing an edge between node i and j with weight k. The IDs of the nodes are between 1 and n inclusive. The weight of each edge will be <= 1000000.
Single number representing the total weight of the minimum spanning tree on this graph. There will be only one possible MST.
Input: 4 5 1 2 10 2 3 15 1 3 5 4 2 2 4 3 40 Output: 17
A score of 100 means you have passed all the test data. In Partial problems, your score reflects the percentage of total correct answers your solution produced.
I looked at the best solutions and don't understand how to scoring is done for this problem.