剑指offer---二叉树的深度

题目描述

输入一棵二叉树，求该树的深度。从根结点到叶结点依次经过的结点（含根、叶结点）形成树的一条路径，最长路径的长度为树的深度。

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

最小深度

class Solution {
public:
    int run(TreeNode *root) {
        if (root==nullptr)
            return 0;
        if (root->left == nullptr) {
            return run(root->right) + 1;
        }
        if (root->right == nullptr){
            return run(root->left) + 1;
        }
        
        int m_left = run(root->left);
        int m_right = run(root->right);
        return min(m_left, m_right)+1;
        
    }
};

用递归求解二叉树深度的分析： https://blog.csdn.net/fisherming/article/details/75096410