剑指38-二叉树的深度

#include<algorithm>

using namespace std;

struct TreeNode {
    int val;
    struct TreeNode *left;
    struct TreeNode *right;
    TreeNode(int x) :
            val(x), left(nullptr), right(nullptr) {
    }
};
class Solution {
public:
    int TreeDepth(TreeNode* pRoot)
    {
        if (!pRoot) return 0;
        return max(TreeDepth(pRoot->left) + 1, TreeDepth(pRoot->right) + 1);
    }
};

链接：https://www.nowcoder.com/questionTerminal/435fb86331474282a3499955f0a41e8b?f=discussion
来源：牛客网

int TreeDepth(TreeNode* pRoot)
    {
     queue<TreeNode*> q;
        if(!pRoot) return 0;
        q.push(pRoot);
        int level=0;
        while(!q.empty()){
            int len=q.size();
            level++;
            while(len--){
                TreeNode* tem=q.front(); //记住该层个数
                q.pop();
                if(tem->left) q.push(tem->left);
                if(tem->right) q.push(tem->right);
            }
        }
        return level;
    }