void sumHelper(TreeNode *root,int psum)
{
if(root == NULL) {
return;
}
psum = 10 * psum + root->val;
if(root->left == NULL && root->right == NULL) {
sum += psum;
}
if(root->left != NULL) {
sumHelper(root->left,psum);
}
if(root->right != NULL) {
sumHelper(root->right,psum);
}
}
vector<vector<int> > combinationSum(vector<int> &candidates, int target) {
vector<vector<int> > result;
vector<int> com;
if(candidates.empty())
return result;
sort(candidates.begin(), candidates.end());
sumHelper(candidates, target, result, com, 0, 0);
return result;
}
void sumHelper(vector<int> &candidates, int target, vector<vector<int> > &result, vector<int> &com, int sum, int k)
{
if(sum > target)
return;
else if(sum == target)
result.push_back(com);
else
{
for(int i = k; i < candidates.size(); ++i)
{
com.push_back(candidates[i]);
sumHelper(candidates, target, result, com, sum+candidates[i], i);
com.pop_back();
}
}
}
int sumNumbers(TreeNode *root) {
sum = 0;
sumHelper(root,0);
return sum;
}
