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;
    }
};