leetcode 129. Sum Root to Leaf Numbers

Given a binary tree containing digits from 

0-9

 only, each root-to-leaf path could represent
a number.

An example is the root-to-leaf path 

1->2->3

 which represents the number 

123

.

Find the total sum of all root-to-leaf numbers.

For example,

1
/ \
2   3

The root-to-leaf path 

1->2

 represents the number 

12

.

The root-to-leaf path 

1->3

 represents the number 

13

.

Return the sum = 12 + 13 = 

25

.

class Solution {
long long int vecnodetonum(vector<pair<TreeNode*, bool> >&quene)
{
long long int re = 0;
for (int i = 0; i < quene.size(); i++)
re += ((long long int)(quene[i].first->val))*powl(10, quene.size() - 1 - i);
return re;
}
public:
int sumNumbers(TreeNode* root) {
if (root == NULL)
return 0;
long long int sum = 0;
vector<pair<TreeNode*, bool> >quene;//bool标识当前节点右子树是否被访问过
quene.push_back(pair<TreeNode*, bool>(root, false));
bool f = true;
while (!quene.empty())
{
if (f&&quene.back().first->left != NULL)
quene.push_back(pair<TreeNode*, bool>(quene.back().first->left, false));
else if (quene.back().first->right != NULL)
{

if (quene.back().second == false)
{
f = true;
quene.back().second = true;
quene.push_back(pair<TreeNode*, bool>(quene.back().first->right, false));
}
else
quene.pop_back();
}
else
{
if (quene.back().first->left == NULL
&&quene.back().first->right == NULL)
sum += vecnodetonum(quene);
quene.pop_back(); f = false;
}
}
return sum;
}
};

accepted