456.cpp

/**
 *    author:   vulkan
 *    created:  02.06.2020 05:14:10 PM
**/
#include <bits/stdc++.h>

using namespace std;

bool find132pattern(vector<int> &arr) {
    int n = arr.size();
    int ak = INT_MIN;
    stack<int> st;
    for (int j = n - 1; j >= 0; --j) {
        if (arr[j] < ak) {
            return true;
        }

        while (not st.empty() and arr[j] > arr[st.top()]) {
            ak = max(ak, arr[st.top()]);
            st.pop();
        }

        st.push(j);
    }

    return false;
}

int main(int argc, char const *argv[]) {
    int n;
    cin >> n;
    vector<int> arr(n);
    for (int i = 0; i <= n - 1; ++i) {
        cin >> arr[i];
    }

    cout << find132pattern(arr);

    return 0;
}