Problem F
Heavy Edges

Björn went to the local grocery store, the T-Fast, and came back carrying an extremely heavy... graph?
In a graph, an edge $e$ is said to be a heavy edge if there exists a simple cycle that contains $e$ in which $e$ is the heaviest edge (equal or heavier weight than all other edges in the cycle).
Björn would like to know how heavy the graph he brought back is. Given a connected, undirected, weighted graph, find the number of heavy edges.
Input
The input will describe the graph that Björn brought back.
The first line of input contains the two integers $N$ and $M$ ($1 \leq N,M \leq 5 \cdot 10^5$), the number of vertices and edges in the graph.
The following $M$ lines each contain three integers $u_i, v_i, w_i$ ($1 \leq u_i, v_i \leq N$, $1 \leq w_i \leq M$), meaning that an edge goes between vertices $u_i$ and $v_i$ of weight $w_i$.
The graph will always be connected, and contains no self-loops or multiple edges. This implies that $u_i \neq v_i$ for all $i = 1,\dots ,M$, and there is at most one edge between each pair of nodes.
Output
Print an integer: the number of heavy edges in the graph.
Scoring
Your solution will be tested on a set of test groups, each worth a number of points. Each test group contains a set of test cases. To get the points for a test group you need to solve all test cases in the test group.
Group |
Points |
Constraints |
$1$ |
$30$ |
All $w_i$ are unique. |
$2$ |
$70$ |
No additional constraints. |
Sample Input 1 | Sample Output 1 |
---|---|
5 7 1 2 7 2 3 6 3 1 5 3 4 4 4 2 3 2 5 2 5 4 1 |
3 |
Sample Input 2 | Sample Output 2 |
---|---|
5 5 1 2 3 2 3 1 3 4 4 4 5 1 5 1 5 |
1 |
Sample Input 3 | Sample Output 3 |
---|---|
5 6 1 2 6 2 3 6 3 1 6 3 4 1 4 5 1 5 1 1 |
3 |
Sample Input 4 | Sample Output 4 |
---|---|
5 4 1 2 3 2 3 3 3 4 3 4 5 3 |
0 |