297. Serialize and Deserialize Binary Tree

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Codec {
public:

    // Encodes a tree to a single string.
    string serialize(TreeNode* root) {
        if(!root)return "#";
        string s=to_string(root->val);
        s+=","+serialize(root->left);
        s+=","+serialize(root->right);
        return s;
    }

    TreeNode*deserial(stringstream &ss){
        string node;
        getline(ss,node,',');
        if(node=="#")return NULL;
        TreeNode*root=new TreeNode(stoi(node));
        root->left=deserial(ss);
        root->right=deserial(ss);

        return root;
    }

    // Decodes your encoded data to tree.
    TreeNode* deserialize(string data) {
        stringstream ss(data);
        return deserial(ss);
    }
};

// Your Codec object will be instantiated and called as such:
// Codec ser, deser;
// TreeNode* ans = deser.deserialize(ser.serialize(root));