FILE_FORMAT

version: 0

File Formats for Maximum Leaf Spanning Tree project

=== Input File Format ===

An input file contains a collection of input graphs.  The first line of the
input file contains one nonnegative integer T, which is the number of graph
descriptions to follow.

Each graph description begins with a line containing a single nonnegative
integer M, which is the number of edges in the graph.  Then follow M lines,
each describing an edge.  Each one of those lines has two distinct integers u
and v, with exactly one space between each of the integers.  Each integer
should be between 0 and MaxNumNodes-1 (see config.go).  The set of nodes in
the input graph is exactly the set of numbers that appear as ends of edges.
Also, all edges in the graph should be in the same connected component.

For example, here is an input file which describes two graphs and is eight
lines long.  The first graph has one edge connecting nodes 0 and 1.  The second
graph has four edges, bringing nodes 0, 1, 4 and 10 into a single component.

2
1
0 1
4
0 1
1 4
1 10
0 10


=== Output File Format ===

The first line of the output file contains a single nonnegative integer T,
which is the number of test case outputs to follow.  This must be equal to the
first line of the input file.

Each test case output begins with a line containing a single nonnegative
integer K, which is the number of edges in the spanning tree.  The next K
lines contain two integers separated by a space, which is an edge in the
spanning tree.

For example, here is a valid output corresponding to the above example input.
The spanning tree in the first graph contains the only edge.  The spanning
tree in the second graph contains three edges.

2
1
0 1
3
1 4
1 0
10 1