minDifference
to infinity and prevNode
to null
.inorderTraversal(node)
that updates prevNode
and minDifference
.
node
is null
, return.inorderTraversal(node.left)
.prevNode
is not null
, update minDifference
with the difference between node.val
and prevNode.val
.prevNode
to node
.inorderTraversal(node.right)
.inorderTraversal(root)
.minDifference
after the traversal is complete.