Example
public class Node
{
public int Value;
public Node Left, Right;
public Node(int item)
{
Value = item;
Left = Right = null;
}
}
class Res
{
public int Val;
}
public class MaximumPathSum
{
Node _root;
int FindMaxUtil(Node node, Res res)
{
if (node == null) return 0;
int l = FindMaxUtil(node.Left, res);
int r = FindMaxUtil(node.Right, res);
int maxSingle = Math.Max(Math.Max(l, r) + node.Value, node.Value);
int maxTop = Math.Max(maxSingle, l + r + node.Value);
res.Val = Math.Max(res.Val, maxTop);
return maxSingle;
}
int FindMaxSum()
{
return FindMaxSum(_root);
}
int FindMaxSum(Node node)
{
Res res = new Res {Val = Int32.MinValue};
FindMaxUtil(node, res);
return res.Val;
}
public static int Main()
{
MaximumPathSum tree = new MaximumPathSum
{
_root = new Node(10)
{
Left = new Node(2),
Right = new Node(10)
}
};
tree._root.Left.Left = new Node(20);
tree._root.Left.Right = new Node(1);
tree._root.Right.Right = new Node(-25)
{
Left = new Node(3),
Right = new Node(4)
};
return tree.FindMaxSum();
}
}
