0 atcoder#ARC102B. [ABC108D] All Your Paths are Different Lengths
[ABC108D] All Your Paths are Different Lengths
Score : points
Problem Statement
You are given an integer . Construct a directed graph that satisfies the conditions below. The graph may contain multiple edges between the same pair of vertices. It can be proved that such a graph always exists.
- The number of vertices, , is at most . The vertices are given ID numbers from to .
- The number of edges, , is at most . Each edge has an integer length between and (inclusive).
- Every edge is directed from the vertex with the smaller ID to the vertex with the larger ID. That is, is one possible topological order of the vertices.
- There are exactly different paths from Vertex to Vertex . The lengths of these paths are all different, and they are integers between and .
Here, the length of a path is the sum of the lengths of the edges contained in that path, and two paths are considered different when the sets of the edges contained in those paths are different.
Constraints
- is an integer.
Input
Input is given from Standard Input in the following format:
Output
In the first line, print and , the number of the vertices and edges in your graph. In the -th of the following lines, print three integers and , representing the starting vertex, the ending vertex and the length of the -th edge. If there are multiple solutions, any of them will be accepted.
4
8 10
1 2 0
2 3 0
3 4 0
1 5 0
2 6 0
3 7 0
4 8 0
5 6 1
6 7 1
7 8 1
In the graph represented by the sample output, there are four paths from Vertex to :
- → → → → with length
- → → → → with length
- → → → → with length
- → → → → with length
There are other possible solutions.
5
5 7
1 2 0
2 3 1
3 4 0
4 5 0
2 4 0
1 3 3
3 5 1