public static bool isUnivalTree(treeNode t)
{
if (t != null)
{
return(univalTree(t, t.val));
}
else
{
return(true);
}
}
public static bool univalTree(treeNode t, int val)
{
if (t == null)
{
return(true);
}
else
{
return(t.val == val && univalTree(t.left, val) && univalTree(t.right, val));
}
}
public static void Main(String[] args)
{
treeNode t, s;
t = new treeNode(2);
t.left = new treeNode(3);
t.right = new treeNode(2);
t.left.left = new treeNode(3);
t.left.right = new treeNode(5);
t.right.left = new treeNode(7);
t.right.right = new treeNode(9);
t.left.left.right = new treeNode(5);
s = new treeNode(3);
s.left = new treeNode(3);
s.right = new treeNode(5);
s.left.right = new treeNode(5);
//s.left.right.left = new treeNode(5);
//Console.WriteLine(isSubtree(t, s));
/*
* A unival tree (which stands for "universal value") is a tree where all nodes under it have the same value.
*
* Given the root to a binary tree, count the number of unival subtrees.
*
* For example, the following tree has 5 unival subtrees:
*
* 0
* / \
* 1 0
* / \
* 1 0
* / \
* 1 1
*
*/
treeNode ut;
ut = new treeNode(0);
ut.left = new treeNode(1);
ut.right = new treeNode(0);
ut.right.left = new treeNode(1);
ut.right.right = new treeNode(0);
ut.right.left.left = new treeNode(1);
ut.right.left.right = new treeNode(1);
Console.WriteLine(isUnivalTree(ut));
Console.WriteLine(univalCount(ut));
}
public static int univalCount(treeNode t)
{
if (isUnivalTree(t))
{
++count;
}
if (t.left != null)
{
univalCount(t.left);
}
if (t.right != null)
{
univalCount(t.right);
}
return(count);
}
public treeNode(int value)
{
val = value;
left = null;
right = null;
}