Problems
Tree PreOrder Traversal
Tree PreOrder Traversal
Implement a PreOrder traversal of a tree. In this traversal the root node is visited first, then the left subtree and finally the right subtree.
Definition of a tree:
// Java
class TreeNode
{
public:
int val;
TreeNode left;
TreeNode right;
TreeNode(int x) {
val = x;
left = NULL;
right = NULL;
};
// C++
class TreeNode
{
public:
int val;
TreeNode *left;
TreeNode *right;
TreeNode(int x) : val(x), left(NULL), right(NULL) {}
};
Implement function PreOrder that prints in one line the vertices of the tree in order of PreOrder traversal. Separate the vertices with one space.
// Java
void PreOrder(TreeNode tree)
// C++
void PreOrder(TreeNode *tree)
Example
During the PreOrder traversal vertices will be printed in the next order: 4 2 1 3 10 9 16.