/
binary_tree_level_order_traversal_II.cpp
52 lines (52 loc) · 1.5 KB
/
binary_tree_level_order_traversal_II.cpp
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/**
* Definition for binary tree
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
struct traverseNode {
TreeNode* node;
int level;
traverseNode(TreeNode* r, int l):node(r), level(l){}
};
class Solution {
queue<traverseNode> traverseQueue;
public:
vector<vector<int> > levelOrderBottom(TreeNode *root) {
vector<vector<int> > answer;
if (root == NULL)
{
return answer;
}
queue<traverseNode> tmpQueue;
traverseQueue.swap(tmpQueue);
traverseQueue.push(traverseNode(root, 1));
while(!traverseQueue.empty())
{
traverseNode topNode = traverseQueue.front();
if (topNode.level > answer.size())
{
vector<int> emptyVector;
answer.push_back(emptyVector);
}
answer[topNode.level - 1].push_back(topNode.node->val);
traverseQueue.pop();
if (topNode.node -> left != NULL)
{
traverseQueue.push(traverseNode(topNode.node->left, topNode.level + 1));
}
if (topNode.node -> right != NULL)
{
traverseQueue.push(traverseNode(topNode.node->right, topNode.level + 1));
}
}
for (int i = 0; i < (answer.size()/2); i++)
{
answer[i].swap(answer[answer.size() - i - 1]);
}
return answer;
}
};