void levelOrderTraversal(TreeNode *root, int level, std::vector<int> &vals)
{
if(root == NULL) return;
if(level == 1)
{
vals.push_back(root->val);
return;
}
levelOrderTraversal(root->left, level-1, vals);
levelOrderTraversal(root->right, level-1, vals);
}
void levelOrderTraversal(BinaryTree *root, queue<int> &traversal, int level)
{
if (root == NULL)
{
return;
}
if (level == 1)
{
traversal.push(root->key);
}
else
{
levelOrderTraversal(root->left, traversal, level - 1);
levelOrderTraversal(root->right, traversal, level - 1);
}
}
/// 层次遍历递归实现
std::vector<int> levelOrderTraversal(TreeNode *root)
{
std::vector<int> vals;
int height = getTreeHeight(root);
for(int level = 1; level <= height; level++)
levelOrderTraversal(root, level, vals);
return vals;
}
queue<int> levelOrderTraversalWrapper(BinaryTree *root, int maxElements)
{
queue<int> traversal;
int level = 1;
while (traversal.size() < maxElements)
{
levelOrderTraversal(root, traversal, level);
level++;
}
return traversal;
}
int main()
{
Node<int> *root;
insert( root, 11 );
insert( root, 9 );
insert( root, 20 );
insert( root, 15 );
insert( root, 25 );
std::cout << "Inorder:";
inorder(root);
std::cout << std::endl;
std::cout << "Level order: \n";
levelOrderTraversal( root );
return 0;
}
