```
class Solution {
private:
vector<int> current_path;
vector<vector<int>> result;
int target;
void dfs(TreeNode* root, int sum){
if(!root) return;
sum+=root->val;
current_path.push_back(root->val);
if(sum==target) if(!root->left && !root->right) result.push_back(current_path);
dfs(root->left, sum);
dfs(root->right, sum);
current_path.pop_back();
}
public:
vector<vector<int>> pathSum(TreeNode* root, int sum) {
target=sum;
dfs(root, 0);
return result;
}
};
```