标签：return val res dfs 二叉 98 root LeetCode
class Solution {
public:
vector<int> dfs(TreeNode* root)//依次返回是否是二叉搜索树，最大值最小值
{
vector<int> res{1,root->val,root->val};
if(root->left)
{
auto l=dfs(root->left);
res[1]=max(res[1],l[1]);
res[2]=min(res[2],l[2]);
if(root->val<=l[1]||!l[0]) res[0]=0;
}
if(root->right)
{
auto r=dfs(root->right);
res[1]=max(res[1],r[1]);
res[2]=min(res[2],r[2]);
if(root->val>=r[2]||!r[0]) res[0]=0;
}
return res;
}
bool isValidBST(TreeNode* root) {
return dfs(root)[0];
}
};
标签：return,
val,
res,
dfs,
二叉,
98,
root,
LeetCode
From： https://www.cnblogs.com/tangxibomb/p/17428264.html