/* 1 You are given a tree of N nodes represented as a set of N-1 pairs of nodes (parent node, child node), each in the range (0..N-1).
Write a program to read the tree and find:
a) the root node
b) all leaf nodes
c) all middle nodes
d) the longest path in the tree
e) * all paths in the tree with given sum S of their nodes
f) * all subtrees with given sum S of their nodes
*/
static void Main(string[] args)
{
//
// 3
// / \
// 5 2
// /|\ \
// 0 1 6 4
Console.SetIn(new StringReader(
@"2 4
3 2
5 0
3 5
5 6
5 1
"));
var tree = new Tree();
string str;
while ((str = Console.ReadLine()) != null)
{
int[] nums = str.Split(null)
.Select(int.Parse)
.ToArray();
tree.AddEdge(nums[0], nums[1]);
}
Debug.Assert(tree.Root.Index == 3);
Debug.Assert(tree.Leaves.SameContents(node => node.Index, new[] { 0, 1, 6, 4 }));
Debug.Assert(tree.InternalNodes.SameContents(node => node.Index, new[] { 5, 2 }));
var longest = tree.LongestPath.Select(n => n.Index);
Debug.Assert(longest.Count() == 5);
Debug.Assert(longest.Contains(4));
Debug.Assert(longest.Contains(2));
Debug.Assert(longest.Contains(3));
Debug.Assert(longest.Contains(5));
Debug.Assert(longest.Contains(0) ||
longest.Contains(1) ||
longest.Contains(6));
Debug.Assert(tree.AllPathsOfSum(6).Count() == 4);
Debug.Assert(tree.AllPathsOfSum(20).First().SameContents(node => node.Index, new[] { 6, 5, 3, 2, 4 }));
Debug.Assert(tree.AllSubtreesOfSum(6).SameContents(node => node.Index, new[] { 6, 2 }));
}
