[LeetCode] Balanced Binary Tree

Problem : 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 subtrees ofevery node never differ by more than one.

1.C++版

/**
* Definition for binary tree
* struct TreeNode {
*     int val;
*     TreeNode *left;
*     TreeNode *right;
*     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
class Solution {
public:
int maxDepth(TreeNode *root) {
if(NULL == root){
return 0;
}

int leftDepth = maxDepth(root->left);
int rightDepth = maxDepth(root->right);

return leftDepth > rightDepth ? leftDepth + 1 : rightDepth + 1;
}

bool isBalanced(TreeNode *root) {
if(NULL == root){
return true;
}

int leftDepth = maxDepth(root->left);
int rightDepth = maxDepth(root->right);

if(abs(leftDepth - rightDepth) > 1){
return false;
}else{
return isBalanced(root->left) && isBalanced(root->right);
}
}
};

2.Java版

3.Python版

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