class Solution {public:        int dfs(TreeNode *p, int pval)    {        if( !p->left && !p->right )        {            int ssum = pval * 10 + p->val;                        return ssum;        }        int rl = 0, rr = 0;        if(p->left)  rl = dfs(p->left, pval * 10 + p->val);        if(p->right) rr = dfs(p->right, pval * 10 + p->val);        return rl + rr;    }    int sumNumbers(TreeNode *root) {        int ret = 0;        if(root)    ret = dfs(root, 0);        return ret;    }};