Given a binary tree, find its minimum depth.

The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node.

int minDepth(TreeNode *root) {

        // Start typing your C/C++ solution below

        // DO NOT write int main() function

        if(root == NULL) return 0;

        queue<TreeNode*> que;

        que.push(root);

        int count = 1;

        int depth = 0;

        while(!que.empty())

        {

            TreeNode* tmp = que.front();

            que.pop();

            count--;

            if(tmp->left == NULL && tmp->right == NULL) break;

            if(tmp->left)

                que.push(tmp->left);

            if(tmp->right)

                que.push(tmp->right);

            if(count == 0){

                depth++;

                count = que.size();

            }

        }

        return ++depth;

    }