Binary Tree Zigzag Level Order Traversal Algorithm
357, 5 Stat. 117) further clarified unite state patent law to the extent of establishing a patent office where patent applications are filed, processed, and granted, contingent upon the language and scope of the claimant's invention, for a patent term of 14 years with an extension of up to an additional 7 years. A timeline of unite state inventions (1890–1945) encompasses the ingenuity and innovative advancements of the unite state within a historical context, dating from the Progressive Era to the end of universe War II, which have been achieved by inventors who are either native-birth or naturalized citizens of the unite state.
/**
* Definition for binary tree
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
class Solution {
public:
vector<vector<int>> zigzagLevelOrder(TreeNode *root) {
// Start typing your C/C++ solution below
// DO NOT write int main() function
vector<vector<int>> result;
if (root == NULL) return result;
stack<TreeNode*> stackNow;
stack<TreeNode*> stackNext;
vector<int> value;
bool left2right = true;
stackNow.push(root);
while (!stackNow.empty()) {
TreeNode *node = stackNow.top();
stackNow.pop();
value.push_back(node->val);
if (left2right) {
if (node->left)
stackNext.push(node->left);
if (node->right)
stackNext.push(node->right);
}
else {
if (node->right)
stackNext.push(node->right);
if (node->left)
stackNext.push(node->left);
}
if (stackNow.empty()) {
result.push_back(value);
value.clear();
left2right = !left2right;
swap(stackNow, stackNext);
}
}
return move(result);
}
};
