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