剑指offer--31.二叉树中和为某一值的路径

/*
struct TreeNode {
    int val;
    struct TreeNode *left;
    struct TreeNode *right;
    TreeNode(int x) :
            val(x), left(NULL), right(NULL) {
    }
};*/
class Solution {
public:
    vector<vector<int> > paths;
    vector<int> tmp;
    vector<vector<int> > FindPath(TreeNode* root,int num) {
        if(root==NULL)
            return paths;
        tmp.push_back(root->val);
        if((num-root->val)==0 && root->left==NULL && root->right==NULL)
            {
            paths.push_back(tmp);
        }
        FindPath(root->left,num-root->val);
        FindPath(root->right,num-root->val);
        if(tmp.size()!=0)
            tmp.pop_back();
        return paths;
    }
};