LEET code -- 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 subtrees of every node never differ by more than 1.

去找底下樹的高度就好

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/** * Definition for a binary tree node. * struct TreeNode { * int val; * struct TreeNode *left; * struct TreeNode *right; * }; */ bool isBalanced(struct TreeNode* root) { int ans=treehigh(root); return ans!=-1? true:false; } int treehigh(struct TreeNode * root){ if(root==NULL)return 1; int le=treehigh(root->left); int ri=treehigh(root->right); if (le==-1 || ri==-1 || abs(le-ri)>1 )return -1; else return le>=ri? 1+le:1+ri; }