劍指offer---二叉樹的深度

題目描述

輸入一棵二叉樹，求該樹的深度。從根結點到葉結點依次通過的結點（含根、葉結點）造成樹的一條路徑，最長路徑的長度爲樹的深度。

/*
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;
        
    }
};

 

用遞歸求解二叉樹深度的分析： https://blog.csdn.net/fisherming/article/details/75096410