class Solution { public: bool VerifySquenceOfBST(vector<int> postorder) { if(postorder.size()<=0) return false; stack<int> stack; int parent = 999999; for (int i = postorder.size() - 1; i >= 0; i--) { int cur = postorder[i]; while (!stack.empty() && stack.top() > cur) {parent = stack.top();stack.pop();} if (cur > parent) return false; stack.push(cur) ; } return true; } };