sword to offer 024

struct TreeNode {
	int val;
	struct TreeNode *left;
	struct TreeNode *right;
	TreeNode(int x) :
			val(x), left(NULL), right(NULL) {
	}
};*/
class  {
vector<vector<int>> res;
vector<int> tmp;
private:
    void Dfs(TreeNode* root, int expectNumber) {
        if(root == nullptr) {
            return ;
        }
        tmp.push_back(root->val);
        expectNumber -= root->val;
        if(expectNumber == 0 && root->left == nullptr && root->right == nullptr) {
            res.push_back(tmp);
        }
        Dfs(root->left, expectNumber);
        Dfs(root->right, expectNumber);
        if(!tmp.empty()) {
            tmp.pop_back();
        }
    }
public:
    vector<vector<int>> FindPath(TreeNode* root,int expectNumber) {
        Dfs(root, expectNumber);
        return res;
    }
};