BST Pre Order Traversal
BST Construction is covered here.
Sample tree:
5
/ \
2 9
/ \ \
1 3 10Pre Order traversal
The root element will come first, then the left child, then the right child.
[5, 2, 1, 3, 9, 10]
Recursive solution:
var traversal = []
function preorder(root) {
if (root == null) return
traversal.push(root.val)
preorder(root.left)
preorder(root.right)
}Iterative solution:
Depth first search, using a stack.
var traversal = []
var stack = []
stack.push(root)
while (stack.length != 0) {
var node = stack.pop()
traversal.push(node.val)
if (root.right) stack.push(root.right)
if (root.left) stack.push(root.left)
}