Sum Root to Leaf Numbers
/**
* Definition for binary tree
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
class Solution {
public:
int sumNumbers(TreeNode *root) {
if(root == NULL){
return 0;
}
if(root->left == NULL && root->right == NULL){
return root->val;
}
vector<TreeNode *> s;
vector<bool> s_visit_left;
vector<bool> s_visit_right;
s.push_back(root);
/*while(s.back()->left != NULL){
s.push_back(s.back()->left);
s_visit_left.push_back(true);
s_visit_right.push_back(false);
}*/
s_visit_left.push_back(false);
s_visit_right.push_back(false);
int result = 0;
while(!s.empty()){
if(s.back()->left == NULL && s.back()->right == NULL){
int temp = 0;;
for(int i = 0; i < s.size(); i++){
temp = temp * 10 + s[i]->val;
}
result += temp;
s.pop_back();
s_visit_left.pop_back();
s_visit_right.pop_back();
}
else if(s.back()->left != NULL && !s_visit_left.back()){
s_visit_left.back() = true;
s.push_back(s.back()->left);
s_visit_left.push_back(false);
s_visit_right.push_back(false);
}
else if(s.back()->right != NULL && !s_visit_right.back()){
s_visit_right.back() = true;
s.push_back(s.back()->right);
s_visit_left.push_back(false);
s_visit_right.push_back(false);
}
else{
s.pop_back();
s_visit_left.pop_back();
s_visit_right.pop_back();
}
}
return result;
}
};