Find Bottom Left Tree Value

Given a binary tree, find the leftmost value in the last row of the 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 Solution {public:    int findBottomLeftValue(TreeNode* root) {        int maxlevel = 0,curlevel;        TreeNode* ROOT;        queue<int> level;queue<TreeNode*> q;q.push(root); level.push(0);ROOT = root;while(q.size()){TreeNode* r = q.front();curlevel = level.front();level.pop();q.pop();if(r->left){q.push(r->left);level.push(curlevel + 1);    }if(r->right){q.push(r->right);level.push(curlevel + 1);    }if(curlevel > maxlevel){maxlevel = curlevel;ROOT = r;}}return ROOT->val;    }};