Preorder Traversal and BST

Given an array arr[ ] of size N consisting of distinct integers, write a program that returns 1 if given array can represent preorder traversal of a possible BST, else returns 0.

• Time : O(n)
• Space : O(n)

class Solution {
  public:
    int canRepresentBST(int arr[], int N) {
        int pos = 0, mi = INT_MIN, ma = INT_MAX;
        vector<pair<int,int>> st;
        st.push_back({mi, ma});
        while(!st.empty() and pos < N) {
            auto p = st.back(); st.pop_back();
            if(p.first < arr[pos] and arr[pos] < p.second) {
                st.push_back({arr[pos], p.second});
                st.push_back({p.first, arr[pos]});
                pos++;
            }
        }
        return pos >= N;
    }
};