Balanced Binary Tree

Balanced Binary Tree

Given a binary tree, determine if it is height-balanced.

For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the two SubtreesEveryNode never differ by more than 1.

C ++ version 1:

#include <iostream>#include <vector>#include <stdlib.h>using namespace std;struct TreeNode{    int val;    TreeNode *left;    TreeNode *right;    TreeNode(int x):val(x),right(NULL),left(NULL){}};class Solution{private:    bool balanced=true;    int height(TreeNode *root){      if(!balanced){        return -1;      }      if(root==NULL){        return 0;      }      int leftH,rightH;      leftH=height(root->left)+1;      rightH=height(root->right)+1;      if(abs(leftH-rightH)>1){        balanced=false;      }      return leftH>rightH?leftH:rightH;    }    bool isBalanced(TreeNode *root){        balanced=true;        height(root);        return balanced;    }};int main(){    cout << "Hello world!" << endl;    return 0;}

C ++ version 2:

/** * Definition for binary tree * struct TreeNode { *     int val; *     TreeNode *left; *     TreeNode *right; *     TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */class Solution {public:    bool checkBalance(TreeNode *node, int &dep)    {        if (node == NULL)        {            dep = 0;            return true;        }                int leftDep, rightDep;        bool leftBalance = checkBalance(node->left, leftDep);        bool rightBalance = checkBalance(node->right, rightDep);                dep = max(leftDep, rightDep)+1;                return leftBalance && rightBalance && (abs(rightDep - leftDep) <= 1);    }        bool isBalanced(TreeNode *root) {        // Start typing your C/C++ solution below        // DO NOT write int main() function        int dep;        return checkBalance(root, dep);    }};

Java version:

/** * Definition for binary tree * public class TreeNode { *     int val; *     TreeNode left; *     TreeNode right; *     TreeNode(int x) { val = x; } * } */public class Solution {   public boolean isBalanced(TreeNode root) {if (root == null)return true; if (getHeight(root) == -1)return false; return true;} public int getHeight(TreeNode root) {if (root == null)return 0; int left = getHeight(root.left);int right = getHeight(root.right); if (left == -1 || right == -1)return -1; if (Math.abs(left - right) > 1) {return -1;} return Math.max(left, right) + 1; }}

　　

Balanced Binary Tree