public static int[] BfsDescendant <TNode, TEdge>(this ITreeGraph <TNode, TEdge> tree, bool skipFirst = false)
where TNode : ITreeNode <TEdge>
where TEdge : IGraphEdge
{
var arr = tree.AsArray();
var res = new int[arr.Length - (skipFirst ? 1 : 0)];
int tar = 0;
if (skipFirst)
{
foreach (var e in arr[tree.Root].Children)
{
res[tar++] = e.To;
}
}
else
{
res[tar++] = tree.Root;
}
int cur = 0;
while ((uint)tar < (uint)res.Length)
{
foreach (var e in arr[res[cur++]].Children)
{
res[tar++] = e.To;
}
}
return(res);
}
public static int[] DfsDescendant <TNode, TEdge>(this ITreeGraph <TNode, TEdge> tree, bool skipFirst = false)
where TNode : ITreeNode <TEdge>
where TEdge : IGraphEdge
{
var arr = tree.AsArray();
var res = new int[arr.Length - (skipFirst ? 1 : 0)];
int cur = 0;
var stack = new Stack <int>(arr.Length);
if (skipFirst)
{
var children = arr[tree.Root].Children;
for (int i = children.Length - 1; i >= 0; i--)
{
stack.Push(children[i].To);
}
}
else
{
stack.Push(tree.Root);
}
while (stack.TryPop(out var ix))
{
res[cur++] = ix;
var children = arr[ix].Children;
for (int i = children.Length - 1; i >= 0; i--)
{
stack.Push(children[i].To);
}
}
return(res);
}
public static int[] DescendantsCounts <TNode, TEdge>(this ITreeGraph <TNode, TEdge> tree)
where TNode : ITreeNode <TEdge>
where TEdge : IGraphEdge
{
var treeArr = tree.AsArray();
var res = new int[treeArr.Length];
var stack = new Stack <(int v, int ci)>(treeArr.Length);
stack.Push((tree.Root, 0));
while (stack.TryPop(out var tup))
{
var(v, ci) = tup;
var children = treeArr[v].Children;
if (ci == 0)
{
res[v] = 1;
}
else
{
res[v] += res[children[ci - 1].To];
}
if (ci < children.Length)
{
stack.Push((v, ci + 1));
stack.Push((children[ci].To, 0));
}
}
return(res);
}