面试题39 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 == NULL)
            return 0;
        int left = TreeDepth(pRoot->left);
        int right = TreeDepth(pRoot->right);
        return left > right ? left + 1 : right + 1;
    }
};

题目描述

输入一棵二叉树，判断该二叉树是否是平衡二叉树。

class Solution {
public:
    
    bool IsBalanced(TreeNode* pRoot, int &depth) {
        if (pRoot == NULL){
            depth = 0;
            return true;
        }
        int left, right;
        if (IsBalanced(pRoot->left, left) && IsBalanced(pRoot->right, right)){
            if (abs(left - right) <= 1){
                depth = left > right ? left + 1 : right + 1;
                return true;
            }
        }
        return false;
    }
    
    bool IsBalanced_Solution(TreeNode* pRoot) {
        int depth = 0;
        return IsBalanced(pRoot, depth);
    }
};