//solution is versy similar to diameter of a tree
// there it is +1 here it is +root.value;
public static int GetMaxPathSum(Node root)
{
MaxPath path = new MaxPath();
path.val = Int32.MinValue;
GetMaxPathSumHelper(root, path);
return(path.val);
}
public static int GetMaxPathSumHelper(Node root, MaxPath path)
{
if (root == null)
{
return(0);
}
// to support case [2,-1] need to take Max(0,func)
var left = Math.Max(0, GetMaxPathSumHelper(root.Left, path));
var right = Math.Max(0, GetMaxPathSumHelper(root.Right, path));
var currMax = left + right + root.Data;
path.val = Math.Max(currMax, path.val);
return(Math.Max(left, right) + root.Data);
}
