L110平衡二叉树

树

给定一个二叉树，判断它是否是高度平衡的二叉树。

解1：递归算树的深度return 1+max(left,right)

bool isBalanced(TreeNode* root) {
        if(checkDepth(root) == -1) return false;
        else return true;
    }
    int checkDepth(TreeNode * root){
        if(root == NULL) return 0;
        int left = checkDepth(root->left);
        if (left == -1) return -1;
        int right = checkDepth(root->right);
        if (right == -1) return -1;
        if(abs(right-left)>1) return -1;
        else return 1+max(left,right);
    }
// 解法2：
bool isBalanced(TreeNode* root) {
         if(root == NULL) return true;
         if (abs(getDepth(root->left)-getDepth(root->right)) >1) return false;
         else{
             if(isBalanced(root->left) && isBalanced(root->right)) return true;
             else return false;
         }
     }
     int getDepth(TreeNode * root){
         if(root == NULL) return 0;
         return 1+max(getDepth(root->left),getDepth(root->right));
     }