package problems.medium;
import problems.utils.TreeNode;
import java.util.List;
import java.util.Stack;
/**
* Created by sherxon on 1/3/17.
*/
public class BinaryTreePreorderTraversal {
private void preOrderIterative(TreeNode x, List<Integer> list) {
Stack<TreeNode> stack=new Stack<>();
stack.add(x);
while (!stack.isEmpty()){
TreeNode treeNode=stack.pop();
list.add(treeNode.val);
if(treeNode.right!=null)
stack.add(treeNode.right);
if(treeNode.left!=null)
stack.add(treeNode.left);
}
}
}