题解 | #二叉树的最大深度#

 * struct TreeNode {
 *	int val;
 *	struct TreeNode *left;
 *	struct TreeNode *right;
 * };
 */

class Solution {
public:
    /**
     * 
     * @param root TreeNode类 
     * @return int整型
     */
    int maxDepth(TreeNode* root) {
        // write code here
        if(!root)
            return 0;
        int ans=0;
        queue<TreeNode *>q;
        TreeNode *cur;
        q.push(root);
        while(!q.empty()){
            int n=q.size();
            ++ans;
            for(int i=0;i<n;i++){
                cur=q.front();
                q.pop();
                if(cur->left)
                    q.push(cur->left);
                if(cur->right)
                    q.push(cur->right);
            }
        }
        return ans;
    }
};